| 1. |
- Ignatova, V.A., et al.
(author)
-
Quantification problems in depth profiling of PWR steels using Ar+ ion sputtering and XPS analysis
- 2006
-
In: Microscopy and Microanalysis. ; 12:5, s. 432-437
-
Journal article (peer-reviewed)abstract
- The oxide scales of AISI 304 formed in boric acid solutions at 300°C and pH = 4.5 have been studied using X-ray photoelectron spectroscopy (XPS) depth profiling. The present focus is depth profile quantification both in depth and chemical composition on a molecular level. The roughness of the samples is studied by atomic force microscopy before and after sputtering, and the erosion rate is determined by measuring the crater depth with a surface profilometer and vertical scanning interferometry. The resulting roughness (20–30 nm), being an order of magnitude lower than the crater depth (0.2–0.5 [mu]m), allows layer-by-layer profiling, although the ion-induced effects result in an uncertainty of the depth calibration of a factor of 2. The XPS spectrum deconvolution and data evaluation applying target factor analysis allows chemical speciation on a molecular level. The elemental distribution as a function of the sputtering time is obtained, and the formation of two layers is observed—one hydroxide (mainly iron–nickel based) on top and a second one deeper, mainly consisting of iron–chromium oxides.
|
|
| 2. |
- Kalaboukhov, Alexei, 1975, et al.
(author)
-
Cationic Disorder and Phase Segregation in LaAlO3/SrTiO3 Heterointerfaces Evidenced by Medium-Energy Ion Spectroscopy
- 2009
-
In: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 103:14, s. 146101-
-
Journal article (peer-reviewed)abstract
- Medium-energy ion spectroscopy (MEIS) has been used to study the depth profile and deduce the distribution of possible cationic substitutions in LaAlO3/SrTiO3 (LAO/STO) heterointerfaces. Analysis of La and Sr peaks in aligned and random MEIS spectra indicates that the surface layers of LAO on an STO substrate are not homogeneous and stoichiometric if the film thickness is less than 4 unit cell layers. This is possibly caused by a redistribution of La and Sr at the interface. Kelvin probe force microscopy reveals an inhomogeneous distribution of the surface potential in a 4 unit cell LAO film, indicating micrometer-sized regions of different compositions. Our findings provide a novel view on the microstructural origin of the electrically conductive interfaces.
|
|
| 3. |
|
|
| 4. |
- Khaibullin, R.I., et al.
(author)
-
An influence of the viscosity of polymer substrate on ion beam synthesis of iron granular films
- 2003
-
In: Nuclear Instruments and Methods in Physics Research B. ; 206, s. 1115-1119
-
Journal article (peer-reviewed)abstract
- Iron granular films were synthesized in silicone polymers by implantation of 40 keV Fe ions with a fluence of1.25x10**17 ion/cm2 into viscous polymer substrates with various viscosity of 20–1000 Pa s. After the implantation the iron-implanted silicone substrates have been cured in the solid rubber-like state on the expiration of 72 h. The influenceof the substrate viscosity on the magnetic properties of the synthesized iron films was studied by ferromagnetic resonance(FMR) spectroscopy. It was shown that magnetic anisotropy and magnetization of the iron granular films is strongly and non-monotonically depended on the viscosity of silicone polymer under irradiation. Particularly, themaximal value of magnetization, 610 G, is observed for iron granular film synthesized at substrate viscosity on order of 70 Pa s. This value is higher than the magnetization of films obtained in silicone substrate implanted with iron ions in fully cured state.
|
|
| 5. |
- Khaibullin, R.I., et al.
(author)
-
Formation of anisotropic ferromagnetic response in rutile (TiO2) implanted with cobalt ions
- 2007
-
In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. ; 257:1-2, s. 369-373
-
Journal article (peer-reviewed)abstract
- The (1 0 0)- and (0 0 1)-monocrystalline plates of rutile (TiO2) were implanted by 40 keV Co+ ions with fluences in wide range of 0.15–1.5 × 1017 ion/cm2 to study the development of ferromagnetism in the diamagnetic TiO2. With increase of fluence the implanted rutile plates reveal sequentially paramagnetic, superparamagnetic, weak ferromagnetic and, eventually, strong anisotropic ferromagnetic response at room temperature. The thermo-magnetic analysis shows that the ferromagnetic samples exhibit two magnetic transitions with temperatures of the ferromagnetic ordering TC1 not, vert, similar 700 K and TC2 not, vert, similar 850 K, correspondingly. Heating of the samples in air strongly suppresses the ferromagnetic phases if the temperature of heating exceeds the corresponding transition temperature. Subsequent high-vacuum annealing restores only the low-temperature ferromagnetic phase. The origin of the two magnetic phases and anisotropy of the ferromagnetism in the Co-implanted rutile are discussed in the model of two cobalt-rich layers with different concentration and valence states of the implanted cobalt.
|
|
| 6. |
- Kondyurin, A.V., et al.
(author)
-
Pulse and continuous ion beam treatment of polyethylene
- 2003
-
In: Vacuum. ; 68, s. 341-347
-
Journal article (peer-reviewed)abstract
- Polyethylene (PE) films were treated by a nitrogen ion beam with an energy of 20 keV at a quasicontinuous regimewith low current density and at a pulse-periodical regime with high current density. IR ATR spectra and UV spectrashowed significant differences in structural changes of PE treated by pulse and continuous treatment at the sameaverage current density. The changes in the molecular structure that are induced by ion beams, i.e. the appearance ofaromatic cycles, unsaturated bonds and carbonyl groups in PE, have a similar qualitative character for all types of ionbeam regimes. However, the same degree of structural changes is achieved at lower dose in the pulse regime than in thecontinuous regime. At equal treatment parameters (ion energy, dose treatment, average current density) the pulseregime leads to a higher concentration of unsaturated and oxygen-containing groups then the continuous regime. Thiseffect at the pulse regime can be explained by the high current density in the single pulse, at which a high localtemperature is generated in the ion track field of the polymer. Probably this leads to a wave of internal stress, and theseeffects additionally stimulate structural changes in the polymer at pulsed ion beam treatment.
|
|
| 7. |
|
|
| 8. |
- Lukashevich, M.G., et al.
(author)
-
Magnetoresistive effect in PET films with iron nanoparticles synthesised by ion implantation
- 2010
-
In: The Open Applied Physics Journal. - 1874-1835. ; 3, s. 1-5
-
Journal article (peer-reviewed)abstract
- Thin polyethyleneterephthalate (PET) layers with Fe nanoparticles (NPs) were synthesised by high-fluence ion implantation. Temperature dependence of conductance and magnetoresitance were studied as a function of ion fluence. It is found that the implantation with fluences of about 1.0×1017 cm-2 causes high enough concentration of metal inclusions to provide conditions for electrical percolation that leads to an insulator-to-metal transition (IMT) in charge carrier transport mechanisms. The magnetoresistance measurements indicate that the magnetic percolation takes place at metal concentrations (fluences) lower than those needed for the electrical percolation. For the samples on insulating side of the IMT, a non-monotonous dependence of resistance in an increasing external magnetic field is observed due to anisotropic magnetoresistive effect and charge carrier scattering on magnetic inclusions. For the samples implanted with fluences > 1.0×1017 cm-2, the magnetoresistance becomes a monotonous decreasing function of the external magnetic field which is typical for ferromagnetic metals that indicates effective magnetic coupling of the iron inclusions.
|
|
| 9. |
- Lukashevich, M.G., et al.
(author)
-
Modification of magnetic properties of polyethyleneterephthalate by iron ion implantation
- 2007
-
In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. ; 257:1-2, s. 589-592
-
Journal article (peer-reviewed)abstract
- Fe+ ions (40 keV) were implanted into polyethyleneterephthalate (PET) films with fluences of (0.25–1.5) × 1017 cm−2. Magnetic properties of the synthesised Fe:PET composites were studied using superconducting quantum interference device (SQUID) technique in temperature range of 2–300 K. For range of fluences (0.5–0.75) × 1017 cm−2 the samples reveal superparamagnetic behaviour at room temperature. At fluences above 0.75 × 1017 cm−2 the strong increase of magnetisation and transition to ferromagnetic properties are registered. Analysis of the magnetic hysteresis loops suggests an easy plane magnetic anisotropy similar to that found for thin magnetic films. Zero-field-cooled (ZFC) and field-cooled (FC) temperature measurements of magnetisation are found to be in agreement with earlier observed formation of Fe nanoparticles (NPs) in the implanted layers. The growth and agglomeration of the NPs forming the quasi-continuous labyrinth-like structure in the polymer film at the highest implantation fluence of 1.5 × 1017 cm−2 is an origin for the transition to the ferromagnetic properties.
|
|
| 10. |
|
|
