| 1. |
- Eyrich, C., et al.
(författare)
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Effects of substitution on the exchange stiffness and magnetization of Co films
- 2014
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 90:23, s. 235408-
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Tidskriftsartikel (refereegranskat)abstract
- An antiferromagnetically coupled FM/NM/FM (FM = ferromagnet, NM = normal metal) trilayer structure responds to an external magnetic field by the formation of a magnetic-moment spring within the FM layers. We show that the exchange stiffness (A ex) of an FM layer can be determined by fitting the field-dependent magnetization, M(H), of the FM/NM/FM trilayer to a micromagnetic model. Using this method, we have measured the exchange stiffness of thin-film Co alloyed with Cr, Fe, Ni, Pd, Pt, and Ru. The results show that the rate at which a substituent element reduces the exchange stiffness is not directly related to its effect on the magnetization of the alloy. The observed trends have been understood by material-specific modeling based on density functional theory within the local density approximation. The stiffness measurements are in agreement with Brillouin light scattering carried out on thicker Co films.
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| 2. |
- Eyrich, C., et al.
(författare)
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Exchange stiffness in thin film Co alloys
- 2012
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 111:7, s. 07C919-
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Tidskriftsartikel (refereegranskat)abstract
- The exchange stiffness (A(ex)) is one of the key parameters controlling magnetization reversal in magnetic materials. We used a method based on the spin spiral formation in two ferromagnetic films antiferromagnetically coupled across a non-magnetic spacer layer and Brillouin scattering to measure A(ex) for a series of Co1-delta X delta (X=Cr, Ni, Ru, Pd, Pt) thin film alloys. The results show that A(ex) of Co alloys does not necessarily scale with M-s; A(ex) approximately decreases at the rate of 1.1%, 1.5%, 2.1%, 3.5%, and 5.6%, while M-s decreases at the rate of 1.1%, 0.5%, 1.1%, 3.7%, and 2.5% per addition of 1 at% of Pt, Ni, Pd, Cr, and Ru, respectively.
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| 3. |
- Girt, Erol, et al.
(författare)
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A method for measuring exchange stiffness in ferromagnetic films
- 2011
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 109:7, s. 07B765-
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Tidskriftsartikel (refereegranskat)abstract
- An exchange stiffness, A(ex), in ferromagnetic films is obtained by fitting the M(H) dependence of two ferromagnetic layers antiferromagnetically coupled across a nonmagnetic spacer layer with a simple micromagnetic model. In epitaxial and textured structures this method allows measuring A(ex) between the crystallographic planes perpendicular to the growth direction of ferromagnetic films. Our results show that A(ex) between [0001] planes in textured Co grains is 1.54 +/- 0.12 x 10(-11) J/m.
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| 4. |
- Kadas, Krisztina, et al.
(författare)
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Structural properties of amorphous metal carbides : Theory and experiment
- 2012
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Ingår i: Acta Materialia. - : Elsevier BV. - 1359-6454 .- 1873-2453. ; 60:12, s. 4720-4728
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Tidskriftsartikel (refereegranskat)abstract
- By means of theoretical modeling and experimental synthesis and characterization, we investigate the structural properties of amorphous Zr-Si-C. Two chemical compositions are selected: Zr0.31Si0.29C0.40 and Zr0.60Si0.33C0.07. Amorphous structures are generated in the theoretical part of our work by the stochastic quenching (SQ) method, and detailed comparison is made regarding the structure and density of the experimentally synthesized films. These films are analyzed experimentally using X-ray absorption spectroscopy, transmission electron microscopy and X-ray diffraction. Our results demonstrate a remarkable agreement between theory and experiment concerning bond distances and atomic coordination of this complex amorphous metal carbide. The demonstrated power of the SQ method opens up avenues for theoretical predictions of amorphous materials in general.
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