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1.	Ahlberg, Martina, et al. (författare) Temperature dependence of magnetic properties in weakly exchange coupled Fe/V superlattices 2013 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 341, s. 142-147 Tidskriftsartikel (refereegranskat)abstract We use Fe(3)/V(x)Fe(3)/V(x) superlattices, x = 16-27 monolayers (ML) to explore the interlayer exchange coupling (IEC) as a function of both spacer layer thickness and temperature. Fe/V is a common model system for studies addressing the IEC, but the behavior in the weakly exchange coupled regime, complemented with the temperature dependence of the magnetic properties, have remained unexplored. We observe clear regions with ferro- and antiferromagnetic coupling, which is manifested in oscillations in the saturation field, the remanence and the critical temperature. The oscillation in the interlayer coupling (J') has a period of 5.8(1) ML. This is approximate to 0.8 ML smaller than observed for Fe(7)/V(x) superlattices which illustrates the influence of the magnetic layer thickness on the interlayer coupling. The temperature dependence of the remanent magnetization was proven to be significantly affected by the strength of the ferromagnetic coupling, leading to high values of the effective critical exponent beta(eff).
2.	Akhter, Shahida, et al. (författare) Magnetic and magnetocaloric properties of Cu1-xZnxFe2O4 (x=0.6, 0.7, 0.8) ferrites 2014 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 367, s. 75-80 Tidskriftsartikel (refereegranskat)abstract The effect of Zn substitution on the magnetic and magnetocaloric properties of Cu1-xZnxFe2O4 (x=0.6, 0.7, 0.8) ferrites over a wide temperature range has been investigated. The polycrystalline samples were synthesized using the solid-state reaction at sintering temperature 1050 degrees C (1323 K) for 2 h and has been characterized by SQUID magnetometry. Magnetization versus temperature showed that all samples exhibit a paramagnetic to ferromagnetic transition with decreasing temperature. The Curie temperature T-c is found to decrease from 373 K for x=0.6 to 140 K for x=0.8 as well as the saturation magnetization Ms which shifts from 100 to 44 emu/gm. The magnetocaloric effect was obtained by measuring a family of M-I1 curves at set temperature intervals and calculating the entropy change, LIS for this system using the Maxwell relation. The AS of all samples increased with increasing applied field and showed a maximum around their respective 'Fe. The entropy change (Delta S) decreased with increasing Zn content, whereas the relative cooling power (RCP) slightly increased. The large RCP and Delta S found in Zn substitution Cu-Zn ferrites will be interesting for magnetic refrigeration near room temperature.
3.	Akman, O., et al. (författare) Magnetic metal nanoparticles coated polyacrylonitrile textiles as microwave absorber 2013 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 327, s. 151-158 Tidskriftsartikel (refereegranskat)abstract Polyacrylonitrile (PAN) textiles with 2 mm thickness are coated with magnetic nanoparticles in coating baths with Ni, Co and their alloys via an electroless metal deposition method. The crystal structure, morphology and magnetic nature of composites are investigated by X-ray Powder diffraction, Scanning Electron Microscopy, and dc magnetization measurement techniques. The frequency dependent microwave absorption measurements have been carried out in the frequency range of 12.4-18 GHz (X and P bands). Diamagnetic and ferromagnetic properties are also investigated. Finally, the microwave absorption of composites is found strongly dependent on the coating time. One absorption peak is observed between 14.3 and 15.8 GHz with an efficient absorption bandwidth of 3.3-4.1 GHz (under -20 dB reflection loss limit). The Reflection loss (RL) can be achieved between -30 and -50 dB. It was found that the RL is decreasing and absorption bandwidth is decreasing with increasing coating time. While absorption peak moves to lower frequencies in Ni coated PAN textile, it goes higher frequencies in Co coated ones. The Ni-Co alloy coated composites have fluctuating curve of absorption frequency with respect to coating time. These results encourage further development of magnetic nanoparticle coated textile absorbers for broadband applications.
4.	Banerjee, Mitali, et al. (författare) Magnetism in FeNiW disordered alloys : Experiment and theory 2010 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 322:21, s. 3558-3564 Tidskriftsartikel (refereegranskat)abstract We report here an experimental study of magnetization of FeNiW alloys at different compositions. We have studied variation of magnetization with temperature (at low external fields) and magnetic field (at low temperatures). The alloy shows para to ferromagnetic transitions across the composition range. We do not find any indication of the spin-glass phase. We have supplemented the experimental work with theoretical analysis using the first-principles tight-binding linear muffin-tin orbitals based augmented space recursion method. Our theoretical estimates of magnetic moment and Curie temperatures agree well with experiment. Our mean-field phase analysis also does not indicate the possibility of a spin-glass.
5.	Bau, L. V., et al. (författare) Observation of mixed-phase behavior in the Mn-doped cobaltite La0.7Sr0.3Co1-xMnxO3 (x=0-0.5) 2010 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 322:6, s. 753-755 Tidskriftsartikel (refereegranskat)abstract Studies on La0.7Sr0.3Co1-xMnxO3 (x=0-0.5) compounds evidence that the interaction between Mn and Co ions in this system is antiferromagnetic super-exchange and not ferromagnetic (FM) double-exchange (DE). As a result, antiferromagnetism and magnetic glassiness develop steadily with increasing Mn content and the system becomes a spin glass at x similar to 0.1. Analyses of high-field magnetization data indicate that the system consists of two major phases: a metallic FM phase which magnetically saturates in rather low field, and an insulating non-FM phase which has a linear dependence of magnetization on magnetic field. In the low doping regime, the fraction of the non-FM component expands with temperature at the expense of the FM phase and becomes maximal at T-C. Ferromagnetism reappears in highly doped (x >= 0.2) compounds due to the presence of DE interaction between the Mn ions. The small volume fraction of the FM phase derived from the M(H) data in high field region supports the coexistence of insulating and FM behaviors in the highly doped samples. (C) 2009 Elsevier B.V. All rights reserved.
6.	Bouhou, S., et al. (författare) Magnetic properties of a ferromagnetic thin film with four spin interaction : A Monte Carlo simulation study 2013 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 339, s. 127-132 Tidskriftsartikel (refereegranskat)abstract Monte Carlo simulation has been used to study the critical behaviors and the magnetic properties of a ferromagnetic thin Ising film with a plaquette four spin interaction. The effects of the ratio r(s) =J(s)/J of the surface exchange interaction to the bulk one and the four spin interaction on phase diagrams are investigated. A number of characteristic behaviors have been found, which include the first-and second-order phase transitions, thus also the tricritical points, triple point and isolated critical point.
7.	Bouhou, S., et al. (författare) Phase diagrams of diluted transverse Ising nanowire 2013 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 336, s. 75-82 Tidskriftsartikel (refereegranskat)abstract In this paper, the phase diagrams of diluted Ising nanowire consisting of core and surface shell coupling by J(cs) exchange interaction are studied using the effective field theory with a probability distribution technique, in the presence of transverse fields in the core and in the surface shell. We find a number of characteristic phenomena. In particular, the effect of concentration c of magnetic atoms, the exchange interaction core/shell, the exchange in surface and the transverse fields in core and in surface shell of phase diagrams are investigated.
8.	Cao, H. W., et al. (författare) First-principles study on electronic and magnetic properties of (Mn,Fe)-codoped ZnO 2014 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853. ; 352:1, s. 66-71 Tidskriftsartikel (refereegranskat)abstract First-principle calculations have been performed to investigate the electronic and magnetic properties of (Mn,Fe)-codoped ZnO within the generalized gradient approximation (GGA) and GGA+U schemes. The formation energy of five different configurations is investigated and the ground state is demonstrated to be ferromagnetic ordering. By applying the U correction, the band gap energy of pure ZnO is close to the experimental values, while the ferromagnetic ordering of the ground state remains unchanged. The ferromagnetic stabilization is mediated by double exchange mechanism. In addition, defects corresponding to Zn-vacancy and O-vacancy cannot enhance the ferromagnetism obviously. These results indicate that (Mn,Fe)-codoped ZnO are promising magneto-electronic and spintronic materials. (C) 2013 Elsevier B.V. All rights reserved
9.	Carva, Karel, et al. (författare) Out-of-plane spin-transfer torques : first-principles study 2010 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 322:9-12, s. 1085-1087 Tidskriftsartikel (refereegranskat)abstract Spin-transfer torques in layered structures are studied with particular attention to their direction. Their direction is in spin valves determined mainly by the properties of the free layer and its interfaces. Situations which lead to a significant component of the torque in the direction perpendicular to both magnetizations present in the spin valve (out-of-plane torque) are described and analyzed. This component may arise from the transmitted spin current, as is demonstrated for a Cu vertical bar Ni vertical bar Cu(001) based system, or from the reflected spin current, which is found to be particularly high for systems with Cr vertical bar Co2MnSi interface. Ab initio calculations were performed for these systems employing the local spin density approximation (LSDA) and the linear muffin-tin orbital (LMTO) method. Information about the direction of the torque was obtained from the spin-mixing conductance.
10.	Delavari, Hamid H., et al. (författare) Modeling of self-controlling hyperthermia based on nickel alloy ferrofluids : Proposition of new nanoparticles 2013 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 335, s. 59-63 Tidskriftsartikel (refereegranskat)abstract In order to provide sufficient heat without overheating healthy tissue in magnetic fluid hyperthermia (MFH), a careful design of the magnetic properties of nanoparticles is essential. We perform a systematic calculation of magnetic properties of Ni-alloy nanoparticles. Stoner-Wohlfarth model based theories (SWMBTs) are considered and the linear response theory (LRT) is used to extract the hysteresis loop of nickel alloy nanoparticles in alternating magnetic fields. It is demonstrated that in the safe range of magnetic field intensity and frequency the LRT cannot be used for the calculation of the area in the hysteresis for magnetic fields relevant for hyperthermia. The best composition and particle size for self-controlling hyperthermia with nickel alloys is determined based on SWMBTs. It is concluded that Ni-V and Ni-Zn are good candidates for self-controlling hyperthermia.
11.	Emmel, M., et al. (författare) Electronic properties of Co2FeSi investigated by X-ray magnetic linear dichroism 2014 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 368, s. 364-373 Tidskriftsartikel (refereegranskat)abstract We present experimental XMLD spectra measured on epitaxial (001)-oriented thin Co2FeSi films, which are rich in features and depend sensitively on the degree of atomic order and interdiffusion from capping layers. Al- and Cr-capped films with different degrees of atomic order were prepared by DC magnetron sputtering by varying the deposition temperatures. The local structural properties of the film samples were additionally investigated by nuclear magnetic resonance (NMR) measurements. The XMLD spectra of the different samples show clear and uniform trends at the L-3,L-2 edges. The Al-capped samples show similar behavior as previous measured XMLD spectra of Co2FeSi0.6Al0.4. Thus, we assume that during deposition Al atoms are being implanted into the subsurface of Co2FeSi. Such an interdiffusion is not observed for the corresponding Cr-capped films, which makes Cr the material of choice for capping Co2FeSi films. We report stronger XMLD intensities at the L-3,L-2 Co and Fe egdes for films with a higher saturation magnetization. Additionally, we compare the spectra with ab initio predictions and obtain a reasonably good agreement. Furthermore, we were able to detect an XMCD signal at the Si Ledge, indicating the presence of a magnetic moment at the Si atoms.
12.	Ghosh, S., et al. (författare) Structural, electronic and magnetic properties of Cr-doped Cd12S12 clusters : A density functional investigation 2010 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 322:6, s. 734-742 Tidskriftsartikel (refereegranskat)abstract We have carried out first-principles density functional investigation of Cd12S12 cluster doped with one (monodoped) and two (bidoped) Cr-atoms, to explore the manifestation of novel magnetism in this family of stable II-VI semiconducting clusters. Different types of possible configurations of the dopant e.g. substitutional, exohedral, endohedral and substitutional-exohedral have been considered. Both for monodoped and bidoped clusters, substitutional doping corresponds to the ground state. Incase of bidoped clusters, the coupling is found to be short-ranged, that depends on the Cr-Cr separation and the local environment. The main competing factors stabilizing ferromagnetic (FM) state in this class of doped nanoclusters are: (a) the FM interaction between two Cr atoms via S atom due to strong p-d hybridization and (b) the short range Cr-Cr direct antiferromagnetic (AFM) interaction. When additional hole is introduced in the system by substituting S with P, in substitutional bidoped clusters, FM state is found to be the ground sate. (C) 2009 Elsevier B.V. All rights reserved.
13.	Hudl, Matthias, et al. (författare) Investigation of the magnetic phase transition and magnetocaloric properties of the Mn2FeSbO6 ilmenite 2013 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 331, s. 193-197 Tidskriftsartikel (refereegranskat)abstract The magnetic phase transition and magnetocaloric properties of both mineral and synthetic melanostibite Mn2FeSbO6 with ilmenite-type structure have been studied. Mn2FeSbO6 orders ferrimagnetically below 270 K and is found to undergo a second-order magnetic phase transition. The associated magnetic entropy change was found to be 1.7 J/kg K for the mineral and 1.8 J/kg K for the synthetic melanostibite for 5 T field change. For the synthetic Mn2FeSbO6 the adiabatic temperature change was estimated from magnetic- and specific heat measurements and amounts to 0.2 K in 1 T field change. Perspectives of the functional properties of Mn2FeSbO6-based materials are discussed.
14.	Ivanov, Sergey A, et al. (författare) Structural and magnetic properties of Mn3-xCdxTeO6 (x = 0, 1, 1.5 and 2) 2012 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 324:8, s. 1637-1644 Tidskriftsartikel (refereegranskat)abstract Mn(3)TeO(6) exhibits a corundum-related A(3)TeO(6) structure and a complex magnetic structure involving two magnetic orbits for the Mn atoms [Ivanov et al., 2011 [3]]. Mn(3-x)Cd(x)TeO(6) (x = 0, 1, 1.5, and 2) ceramics were synthesized by solid state reaction and investigated using X-ray powder diffraction, electron microscopy, and calorimetric and magnetic measurements. Cd(2+) replaces Mn(2+) cations without greatly affecting the structure of the compound. The Mn and Cd cations were found to be randomly distributed over the A-site. Magnetization measurements indicated that the samples order antiferromagnetically at low temperature with a transition temperature that decreases with increasing Cd doping. The nuclear and magnetic structure of one specially prepared (114)Cd containing sample: Mn(1.5) (114)Cd(1.5)TeO(6), was studied using neutron powder diffraction over the temperature range 2-295 K. Mn(1.5) (114)Cd(1.5)TeO(6) was found to order in an incommensurate helical magnetic structure, very similar to that of Mn(3)TeO(6) [Ivanov et al., 2011 [3]]. However, with a lower transition temperature and the extension of the ordered structure confined to order 240(10) angstrom.
15.	Jena, Ambika Prasad, et al. (författare) Study of the effect of magnetic ordering on order-disorder transitions in binary alloys 2014 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 360, s. 15-20 Tidskriftsartikel (refereegranskat)abstract We set up a mean-field approximation in a random king model characterized by two order parameters: the local sublattice magnetization and a mean-field occupation variable which act as an order parameter for the order-disorder transition. In the effective model Hamiltonian the two order-parameters are coupled. We solve the coupled equations arising from this to describe the total phase diagram. The exchange energies for FeCo alloys have then been accurately obtained from first-principles based on the technique of orbital peeling and a Monte Carlo analysis using a coupled Metropolis-Kawasaki updating has been carried out. Our results reasonably successfully agree with earlier experimental data.
16.	Jena, Ambika Prasad, et al. (författare) Study of the effect of short ranged ordering on the magnetism in FeCr alloys 2014 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 349, s. 156-158 Tidskriftsartikel (refereegranskat)abstract For the study of magnetism in systems where the local environment plays an important role, we propose a marriage between the Monte Carlo simulation and Zunger's special quasi-random structures. We apply this technique on disordered FeCr alloys and show that our estimates of the transition temperature is in good agreement with earlier experiments.
17.	Khot, V, et al. (författare) Induction heating studies of combustion synthesized MgFe2O4 nanoparticles for hyperthermia applications 2013 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier. - 0304-8853 .- 1873-4766. ; 332:April, s. 48-51 Tidskriftsartikel (refereegranskat)abstract The structural, magnetic and ac magnetically induced heating characteristics of combustion synthesized MgFe2O4 nanoparticles have been investigated for application in magnetic particle hyperthermia. As prepared nanoparticles showed ferrimagnetic behavior at room temperature with magnetization of about 33.83 emu/g at ±15 kOe. The solid state MgFe2O4 nanoparticles exhibited specific absorption rate (SAR) of about 297 W/g at physiological safe range of frequency and amplitude. The increase in SAR and heating temperature in ac magnetic field was thought to be due to enhancement in magnetic hysteresis loss caused by dipole–dipole interactions in combustion synthesized MgFe2O4 nanoparticles.
18.	Kravets, A. F., et al. (författare) Exchange-induced phase separation in Ni-Cu films 2012 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 324:13, s. 2131-2135 Tidskriftsartikel (refereegranskat)abstract Magneto-structural properties of films of diluted ferromagnetic alloys NixCu1-x in the concentration range 0.7 < x < 1.0 are studied experimentally. Films deposited by magnetron sputtering show partial phase separation, as evidenced by structural analysis and ferromagnetic resonance measurements. The phase diagram of the NixCu1-x bulk system is obtained using numerical theoretical analysis of the electronic structure, taking into account the interatomic exchange interactions. The results confirm the experimentally found partial phase separation, explain it as magnetic in origin, and indicate an additional metastable region connected with the ferromagnetic transition in the system.
19.	Mardinoglu, Adil, 1982 (författare) Many particle magnetic dipole–dipole and hydrodynamic interactions in magnetizable stent assisted magnetic drug targeting 2010 Ingår i: Journal of Magnetism and Magnetic Materials. - 0304-8853. ; 322:15, s. 2087-2094 Tidskriftsartikel (refereegranskat)abstract The implant assisted magnetic targeted drug delivery system of Avilés, Ebner and Ritter is considered both experimentally (in vitro) and theoretically. The results of a 2D mathematical model are compared with 3D experimental results for a magnetizable wire stent. In this experiment a ferromagnetic, coiled wire stent is implanted to aid collection of particles which consist of single domain magnetic nanoparticles (radius ). In order to model the agglomeration of particles known to occur in this system, the magnetic dipole–dipole and hydrodynamic interactions for multiple particles are included. Simulations based on this mathematical model were performed using open source C++ code. Different initial positions are considered and the system performance is assessed in terms of collection efficiency. The results of this model show closer agreement with the measured in vitro experimental results and with the literature. The implications in nanotechnology and nanomedicine are based on the prediction of the particle efficiency, in conjunction with the magnetizable stent, for targeted drug delivery.
20.	Mardinoglu, Adil, 1982 (författare) Theoretical modelling of physiologically stretched vessel in magnetisable stent assisted magnetic drug targetingapplication 2011 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853. ; 323:3-4, s. 324-329 Tidskriftsartikel (refereegranskat)abstract The magnetisable stent assisted magnetic targeted drug delivery system in a physiologically stretched vessel is considered theoretically. The changes in the mechanical behaviour of the vessel are analysed under the influence of mechanical forces generated by blood pressure. In this 2D mathematical model a ferromagnetic, coiled wire stent is implanted to aid collection of magnetic drug carrier particles in an elastic tube, which has similar mechanical properties to the blood vessel. A cyclic mechanical force is applied to the elastic tube to mimic the mechanical stress and strain of both the stent and vessel while in the body due to pulsatile blood circulation. The magnetic dipole–dipole and hydrodynamic interactions for multiple particles are included and agglomeration of particles is also modelled. The resulting collection efficiency of the mathematical model shows that the system performance can decrease by as much as 10% due to the effects of the pulsatile blood circulation.
21.	Monsen, Asmund, et al. (författare) Thickness dependence of dynamic and static magnetic properties of pulsed laser deposited La0.7Sr0.3MnO3 films on SrTiO3(001) 2014 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 369, s. 197-204 Tidskriftsartikel (refereegranskat)abstract We present a comprehensive study of the thickness dependence of static and magneto-dynamic magnetic properties of La0.7Sr0.3MnO3. Epitaxial pulsed laser deposited La0.7Sr0.3MnO3 (001) thin films in the range from 3 unit cell (uc) to 40 uc (1.2-16 nm) have been investigated through ferromagnetic resonance (FMR) spectroscopy and SQUID magnetometry at variable temperature. Magnetodynamically, three different thickness, d, regimes are identified: 20 uc less than or similar to d uc where the system is bulk like, a transition region 8 uc < d less than or similar to 20 uc where the FMR linewidth and the position depend on thickness and d=6 uc which displays significantly altered magnetodynamic properties, while still displaying bulk magnetization. Magnetization and FMR measurements are consistent with a nonmagnetic volume corresponding to similar to 4 uc. We observe a reduction of Curie temperature (T-c) with decreasing thickness, which is coherent with a mean field model description. The reduced ordering temperature also accounts for the thickness dependence of the magnetic anisotropy constants and resonance fields. The clamping of the system is strongly thickness dependent, and is for thin films dominated by thickness dependent anisotropies, yielding both a strong two-magnon scattering close to T-c and a low temperature broadening. For the bulk like samples a large part of the broadening can be linked to spread in magnetic anisotropies attributed to crystal imperfections/domain boundaries of the bulk like film.
22.	Montoya, Eric, et al. (författare) Broadband ferromagnetic resonance system and methods for ultrathin magnetic films 2014 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 356, s. 12-20 Tidskriftsartikel (refereegranskat)abstract Spintronics requires the development, of magnetic thin film structures having a wide range of magnetic properties. Ferromagnetic resonance (FMR) is a well understood experimental technique that has proven to be an invaluable tool to probe the static and dynamic magnetic properties of ultrathin films, multilayer nanostructures, and super lattices. In order to achieve a full characterization of thin film materials, one Reeds to carry out FMR measurements at a wide range of microwave frequencies. In this paper, we show that one does not have to use a broadband vector network analyzer; similar performance can be achieved by using a broadband microwave signal generator, a coplanar waveguide, and a broadband microwave detector. To obtain a good signal to noise ratio, one needs to employ a modulation technique in order to use lock-in detection; in this paper, we use low frequency external field modulation (105 Hz) and microwave power amplitude pulse modulation (10 kHz). The sensitivity and he performance of this broadband microwave system is demonstrated on two types of samples: molecular beam epitaxy grown single crystal GaAs(001)/Fe/Au and sputter deposit:cc! textured Si(111)/Ta/Ru/Co/Ru superlattice structures. The samples were mounted on a coplanar waveguide, allowing one a broadband measurement, similar to 0.1-50 GHz, of DC field swept FMR signals. The results are compared to traditional field swept, field modulated measurements in microwave cavity resonators. Despite the fact that the FMR signal can be very different from that obtained by standard microwave cavities, we show that the analysis of the FMR signal is fairly simple using an admixture of the in-phase and out-of-phase components of rf susceptibility and that the resulting fitted magnetic parameters are in excellent agreement. Additionally, we demonstrate that microwave power amplitude pulse modulation can be used to greatly speed up data collection times, especially for very weak and broad FMR signals.
23.	Nadutov, V. M., et al. (författare) Anti-Invar properties and magnetic order in fcc Fe-Ni-C alloy 2011 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 323:22, s. 2786-2791 Tidskriftsartikel (refereegranskat)abstract Anti-Invar effect was revealed in the fcc Fe-25.3%Ni-0.73%C (wt%) alloy, which demonstrates high values of thermal expansion coefficient (TEC) (15-21) x 10(-6) K(-1) accompanied by almost temperature-insensitive behavior in temperature range of 122-525 K. Alloying with carbon considerably expanded the low temperature range of anti-Invar behavior in fcc Fe-Ni-based alloy. The Curie temperature of the alloy T(C) = 195 K was determined on measurements of temperature dependences of magnetic susceptibility and saturation magnetization. The Mossbauer and small-angle neutron scattering (SANS) experiments on the fcc Fe-25.3%Ni-(0.73-0.78)%C alloys with the varying temperatures below and above the Curie point and in external magnetic field of 1.5-5 T were conducted. Low value of the Debye temperature Theta(D) = 180 K was estimated using the temperature dependence of the integral intensity of Mossbauer spectra for specified temperature range. The inequality B(eff) = (0.7-0.9)B(ext) was obtained in external field Mossbauer measurement that points to antiferromagnetically coupled Fe atoms, which have a tendency to align their spins perpendicular to B(ext). Nano length scale magnetic in homogeneities nearby and far above T(C) were revealed, which assumed that it is caused by mixed antiferromagnetically and ferromagnetically coupled Fe atom spins. The anti-Invar behavior of Fe-Ni-C alloy is explained in terms of evolution of magnetic order with changing temperature resulting from thermally varied interspin interaction and decreasing stiffness of interatomic bond.
24.	Nguyen, Thi Ngooc Ahn, et al. (författare) Co/Pd (4)-Co-Pd-NiFe spring magnets with highly tunable and uniform magnetization tilt angles 2012 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 324:22, s. 3929-3932 Tidskriftsartikel (refereegranskat)abstract By varying the Pd thickness (t(Pd)) from 0 to 8 nm in [Co/Pd](4)/Co/Pd(t(Pd))/NiFe exchange springs, we demonstrate (i) continuous tailoring of the exchange coupling between a [Co/Pd](4)/Co layer with perpendicular anisotropy, and a NiFe layer with an in-plane easy axis, (ii) tuning of the NiFe out-of-plane magnetization angle from 20 degrees to 80 degrees, and(iii) an up to two-fold increase in the NiFe damping. The partial decoupling also results in a highly uniform NiFe magnetization. These properties make [Co/Pd](4)/Co/Pd(t(Pd))/NiFe spring magnets ideal candidates for use as tilted polarizers, by combining stable and well-defined spin directions of its carriers with a high degree of angular freedom. (C) 2012 Elsevier B.V. All rights reserved.
25.	Nikam, Dipali, et al. (författare) Study of AC Magnetic Heating Characteristics of Co0.5Zn0.5Fe2O4 nanoparticles for magnetic Hyperthermia therapy 2014 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier. - 0304-8853 .- 1873-4766. ; 349, s. 208-213 Tidskriftsartikel (refereegranskat)abstract Structural, magnetic properties and an alternating current (AC) magnetic heating characteristics of Co0.5Zn0.5Fe2O4 nanoparticles (CZF NPs) have been investigated with respect to the possible application for magnetic hyperthermia treatments. The Specific Absorption Rate (SAR) was measured in alternating magnetic fields of 167.5–335.2 Oe at fixed frequency of 265 kHz. CZF NPs were fabricated by the chemical co-precipitation method using sodium hydroxide (NaOH) as the precipitating agent. The morphology of the particles was analysed by Transmission Electron microscopy (TEM). The TEM reveals that the grains are nearly spherical in shape with average particles size of 19 nm. X-ray diffraction pattern indicated the sole existence of cubic spinel phase of CZF NPs. The magnetization (Ms) of CZF NPs was measured at room temperature (300 K) using a Vibrating Sample Magnetometer (VSM). The magnetic heating ability of NPs was studied with an induction heating system. A highest SAR value of 114.98 W/g for 5 mg/mL sample concentration (265 kHz, 335.2 Oe) was determined
26.	Phadatare, Manisha R., et al. (författare) Studies on polyethylene glycol coating on NiFe2O4 nanoparticles for biomedical applications 2012 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier. - 0304-8853 .- 1873-4766. ; 324:5, s. 770-772 Tidskriftsartikel (refereegranskat)abstract The NiFe2O4 nanoparticles were prepared by the combustion method and these nanoparticles were successfully coated with polyethylene glycol (PEG) for the possible biomedical applications such as magnetic resonance imaging, drug delivery, tissue repair, magnetic fluid hyperthermia etc. The structural and magnetic characterizations of NiFe2O4 nanoparticles were carried out by x-ray diffraction and vibrating sample magnetometry techniques, respectively. The morphology of the uncoated and coated nanoparticles was studied by scanning electron microscopy. The existence of PEG layer on NiFe2O4 nanoparticles was confirmed by fourier transform infrared spectroscopy technique.
27.	Ronneteg, Sabina, et al. (författare) A neutron powder diffraction study of the helimagnetic structure of TlCo2Se2−xSx 2010 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 322:6, s. 681-685 Tidskriftsartikel (refereegranskat)abstract The magneti clayer structure of TlCo2Se2-xSx has been thoroughly re-investigated with neutron powder diffraction. The cobalt magnetic moments are ferromagnetically arranged with in the layers, but the interlayer coupling differs profoundly with varying composition (x): the spins in TlCo2Se2 form a helix along the c-axis with a turning-angle of similar to 119 degrees at 1.4 K. This kind of helical structure prevails for 0 <= x <= 1.5 with a gradual decrease of the angle with increasing sulphur content, down to 34 degrees, showing an almost linear relationship with the interlayer distance of Co-Co. For x >= 1.75 the interlayer couplingchanges to ferromagnetic. Unexpectedly, two helices were found to coexist at x = 0.5 and x = 1.0. The interaction between adjacent cobalt layers is there characterized by an incommensurate angle (106 degrees, resp., 73 degrees) together with a commensurate angle of 90 degrees. The magnetic structures have been refined as two magnetic phases, each having a characteristic wave vector. A tentative model where the symmetry of the structure and the interlayer distance compete is considered for explaining the simultaneous occurrence of the two kinds of diffraction profile satellites.
28.	Rusz, Jan, et al. (författare) Quantitative magnetic measurements with transmission electron microscope 2010 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 322:9-12, s. 1478-1480 Tidskriftsartikel (refereegranskat)abstract We briefly review the state-of-the-art electronmagnetic chiraldichroism experiments and theory with focus on quantitative measurements of the atom-specific orbital to spin moment ratio m(1)/m(s). Our approach of quantitative method, based on reciprocal space mapping of the magnetic signal, is described. We discuss additional symmetry considerations for m(1)/m(s) measurements, which are present due to dynamical diffraction effects. The selead to a preference for the 3-beam orientation of the sample. Further on, we describe a method of correcting a symmetries present due to imperfect 3-beam orientation-the so-called double-difference correction.
29.	Salunkhe, A, et al. (författare) Low temperature combustion synthesis and magnetostructural properties of Co–Mn nanoferrites 2014 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier. - 0304-8853 .- 1873-4766. ; 352, s. 91-98 Tidskriftsartikel (refereegranskat)abstract In the present work, Co1−xMnxFe2O4 nanoparticles were synthesized by the low-temperature auto-combustion method. The thermal decomposition process was investigated by means of differential and thermal gravimetric analysis (TG-DTA) that showed the precursor yield the final product above 450 °C. The phase purity and crystal lattice symmetry were estimated from X-ray diffraction (XRD). Microstructural features observed by scanning electron microscopy (SEM) demonstrates that the fine clustered particles were formed with an increase in average grain size with Mn2+ content. Fourier transform infrared spectroscopy (FTIR) study confirms the formation of spinel ferrite. Room temperature magnetization measurements showed that the magnetization Ms increases from 29 to 60 emu/g and Hc increases from 13 to 28 Oe with increase in Mn2+ content, which implies that these materials may be applicable for magnetic data storage and recording media.
30.	Sasnovskaya, V, et al. (författare) Preparation and magnetic properties of Mn-12 clusters with 4-cyanobenzenecarboxylate ligand, [Mn12O12(O2CC6H4-p-CN)(16)(H2O)(4)] and its tetraphenylphosphonium salts 2012 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 324:18, s. 2746-2752 Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract The new Mn12 magnetic clusters with 4-cyanobenzenecarboxylate ligand, [Mn12O12(O2CC6H4-p-CN)16(H2O)4] (1) and its singly (2) and doubly (3) reduced analogues as their tetraphenylphosphonium salts, have been synthesized and characterized by elemental analyses, Raman, ESI-MS spectra and magnetic measurements with a SQUID magnetometer. Unlike the known Mn12 oxocarboxylate clusters, which are very soluble in CH3CN or CH2Cl2, the complex 1 is not dissolved in organic solvents providing an indication for strong intermolecular interactions which lead to strong dipole-dipole interactions between clusters and affect the magnetic behaviour. The one-electron and two-electron reduced clusters (2, 3) contain the bulk counterion and dissolve in CH3CN. They show magnetic properties characteristic for anion Mn12 single-molecule magnets.
31.	Sertkol, M., et al. (författare) Synthesis and magnetic characterization of Zn0.7Ni0.3Fe2O4 nanoparticles via microwave-assisted combustion route 2010 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 322:7, s. 866-871 Tidskriftsartikel (refereegranskat)abstract We report on the synthesis of Zn0.7Ni0.3Fe2O4 nanoparticles via microwave assisted combustion route by using urea as fuel. XRD and FT-IR analyses confirm the composition and structure as spinel ferrite. The crystallite size estimated from XRD (16.4nm) and the magnetic core size(15.04nm) estimated from VSM agree well, while a slightly smaller magnetic diameterre reflects a very thin magnetically dead layer on the surface of the nanoparticles. Morphological investigation of the products was done by TEM which revealed the existence of irregular shapes such spherical, spherodial and polygon. Magnetization measurements performed on Zn0.7Ni0.3Fe2O4 nanoparticles showed that saturation was not attained at even in the high magnetic field. The sample shows superparamagnetic behavior at around the room temperature and ferromagnetic behavior below the blocking temperature which is measured as 284 K.
32.	Siesing, Leif, et al. (författare) Soft magnetic moldable composites: Properties and applications 2012 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853. ; 324:18, s. 2717-2722 Tidskriftsartikel (refereegranskat)abstract A new type of electromagnetic soft magnetic material (SMM) is introduced, based on spherical iron powder particles and a suitable polymer binder. A key feature of this material is that it can be cast or molded into almost any 3D shape, hence the denotation soft magnetic moldable composite ((SMC)-C-2). The SM2C is compared with a set of reference materials, such as ferrites, laminated steels, and soft magnetic composites, in terms of primary properties such as permeability and loss, and other properties, such as thermal conductivity and manufacturability. The SM2C has the obvious disadvantage of relatively low permeability, but offers benefits such as relatively low losses and high potential for close integration into electromagnetic circuits. Some recent SM2C applications are illustrated, and design and manufacturing aspects are discussed. (C) 2012 Elsevier B.V. All rights reserved.
33.	Singh, Prashant, et al. (författare) Magnetic transitions in Ni1-xMox and Ni1-xWx disordered alloys 2011 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 323:20, s. 2478-2482 Tidskriftsartikel (refereegranskat)abstract We present a mean-field study of the magnetic phase diagram of Ni1-xMox and Ni1-xWx alloys. The pair energies that enter the internal energy part of the free energy are obtained from a first-principles calculation. We try to understand why spin-glass phase is not observed in these alloys.
34.	Tarras-Wahlberg, Nils, 1973, et al. (författare) Magnetization and Mossbauer study of partially oxidized iron cluster films deposited on HOPG 2014 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 367, s. 40-46 Tidskriftsartikel (refereegranskat)abstract Iron clusters produced in a laser vaporization source were deposited to form cluster assembled thin films with different thicknesses on highly oriented pyrolytic graphite substrates. The development of oxidation of the clusters with time, up to three years, was investigated by magnetic measurements using an alternating gradient magnetometer. Furthermore, to receive information about the oxidation states, clusters of 57Fe were studied using Mossbauer spectroscopy. The magnetic analysis shows a time evolution of the saturation magnetization, remanence, and coercivity, determined from the hysteresis curves characteristic of a progressing oxidation. The different thicknesses of the iron cluster films as well as a protective layer of vanadium influence the magnetic properties when the samples are subjected to oxidation with Lime. While the saturation magnetization and remanence decrease and reach half the initial values for almost all the samples after three years, the coercivity increases for all samples and is more substantial for the thickest sample with a vanadium protective layer. This value is three folded after three years. Furthermore, based on a core-shell model and using the saturation magnetization values we have been able to quantitatively calculate the amount of the increase of Fe-oxide as a function of time. The Mossbauer spectroscopy shows peaks corresponding to iron metal and maghemite.
35.	Yadav, Manoj K., et al. (författare) Tuning magnetism of MnO by doping with 2p elements 2010 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 322:2, s. 253-256 Tidskriftsartikel (refereegranskat)abstract We show that the antiferromagnetic coupling between Mn atoms in MnO can be tuned to a ferromagneticone by doping it with a small concentration of 2p elements like boron, carbon and nitrogen. Our ab initio density functional calculations in the Hubbard U framework show that the coupling between Mn atoms turns ferromagnetic for 3 at% B doping. B is found to be the most effective one in stabilizing ferromagnetism. We discuss the role of 2p states of the dopant atoms to explain the trend of ferromagnetism in MnO. (C) 2009 Elsevier B. V. All rights reserved.
36.	Zamani, Atieh, et al. (författare) Tuning magnetic properties by hydrogen implantation in amorphous Fe100-xZrx thin films 2013 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 346, s. 138-141 Tidskriftsartikel (refereegranskat)abstract Thin films of amorphous Fe100-xZrx (x=7.6-12.9 at%) were synthesized by dc-magnetron sputtering. Samples with compositions of x=11.6 and 12.0 at% were hydrogenated by implantation. The Curie temperature increases with hydrogen content from 232 K for as-grown Fe88Zr12 to 370 K for a sample hydrogenated to 31 at%. The coercivity decreases dramatically upon hydrogenation, yielding films with tunable transition temperatures and soft magnetic properties.

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