• Journal of the Korean institute of surface engineering
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• v.29 no.6
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• pp.628-633
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• 1996

Large saturation magnetization $4pM_s$ is essentially required for soft magnetic thin layers used in magnetic recording devices. Amorphous Co-based alloys and Fe-Co alloys may be regarded as one of the candidates for soft magnetic materials which possess large $4\piM_s$. Some preparation process to improve soft magnetism of these films were performed in this study. Addition of Ta seemed to be effective to change the magnetostriction constant $\lambda$ from positive value to negative one. The magnetoelastic energy $K_e$ is strongly dependent on $\lambda$. $(Co_{95.7}Zr_{4.3})_{100-x}Ta_x$ films with $K_e$ of negative value have sufficiently soft magnetic characteristics. $Fe_{90}Co_{10}$ alloy exhibits extremely large $4\piM_s$, of about 24 kG. Addition of N and Ta to $Fe_{90}Co_{10}$ films improved the soft magnetism of them. The $Fe_{82.0}Co_{7.6}Ta_{10.4}$:N/Ti multilayered films exhibit better soft magnetic properties and better thermal stability than Fe-Co-Ta:N singlelayer films.

• Journal of Magnetics
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• v.13 no.4
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• pp.115-119
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• 2008

The authors predicted that $Co_2HfSi$, a $Co_2$-based full Heusler alloy, is being a half-metallic ferromagnet by first-principles calculations using the all electron full-potential linearized augmented plane wave method which adopts the generalized gradient approximation. The integer value of the calculated total magnetic moment of 2.00 ${\mu}_B$ per formula unit and a spin gap of 0.69 eV in spin down state confirmed the half-metallicity of bulk $Co_2HfSi$. For the $Co_2HfSi$(001) surface, we considered two possible surface terminations, namely, Co terminated and HfSi terminated surfaces. It was found that half-metallicity was retained at the HfSi-terminated surface but not at the Co-terminated surface. The magnetic moment of surface Co atoms in the Co-terminated surface was slightly lower than that of Co atoms in deep inner-layers, whereas the magnetic moments of Hf and Si atoms at the HfSi-terminated surface were almost same as those in deep inner-layers.

• Journal of the Korean Magnetics Society
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• v.17 no.3
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• pp.109-113
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• 2007

We investigated the magnetic properties of VRu(001) surface by using the all electron full-potenial linearized augmented planewave (FLAPW) energy band method within the GGA. We consider two different configurations, V and Ru surface layers, respectively. The V atoms in surface layer was calculated to have large magnetic moment of $1.71_{{\mu}_B}$ while the Ru surface layer to have nearly nonmagnetic state. The calculated spin-polarized density of states. spin density contour, and charge density were discussed in relation to the magnetic properties of VRu(001) surface.

• Journal of Magnetics
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• v.12 no.2
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• pp.59-63
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• 2007

Ferromagnet/Semiconductor heterostructures have attracted much attention because of their potential applications in spintronic devices. We investigated the electronic structures and magnetism of monolayer Fe on $CuGaSe_2(001)$ by using the all-electron full-potential linearized augmented plane-wave method within a generalized gradient approximation. We considered the monolayer Fe deposited on both the CuGa atoms terminated (CuGa-Term) and the Se atom terminated (Se-Term) surfaces of $CuGaSe_2(001)$. The calculated magnetic moment of the Fe atom on the CuGa-Term was about $2.90\;{{\mu}_B}$. Those of the Fe atoms on the Se-Term were in the range of $2.85-2.98\;{{\mu}_B}$. The different magnetic behaviors of the Fe atoms on two different surfaces were discussed using the calculated layer-projected density of states.

• Journal of the Korean Magnetics Society
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• v.21 no.4
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• pp.141-146
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• 2011

We will introduce the surface magneto-optic Kerr effect (SMOKE), which is one of the most helpful experimental methods in the area of surface magnetism for the last two decades. The basic magnetic characteristics of magnetic thin film is the most essential part for the further understanding and application. For example, the possibility of the realization of ferromagnetism for a single layer of iron, its Curie temperature far below that of bulk iron, and the direction of easy axis are the fundamental questions for the spintronic application. SMOKE is an efficient method to answer for the questions above.

• Journal of Magnetics
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• v.15 no.2
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• pp.45-50
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• 2010

We investigated the magnetism of vanadium monolayers on a Pd(001) surface. The electronic structure and the magnetic properties of the V/Pd(001) system were determined with the use of the full-potential linearized augmented plane-wave method within the general gradient approximation. Three magnetic configurations were studied: non-, ferro-, and antiferromagnetic. From the total energy calculations, we found that the V/Pd(001) system is the most stable in the antiferromagnetic configuration. The importance of relaxation on the magnetic properties of the systems was also studied. It was found that the Pd(001) surface covered with a V monolayer undergoes considerable relaxation in which the spacing between Pd layers increases in all three magnetic configurations. Contrary to the Pd interlayer spacing, the distance between the V overlayer and the topmost Pd layer is reduced. The interlayer spacing between the V overlayer and the Pd surface layer is the largest for the antiferromagnetic configuration. In the relaxed antiferromagnetic structure, the magnitude of the calculated magnetic moments on the V atoms was $1.31\;{\mu}_B$. The presence of the vanadium monolayer does not affect the paramagnetic properties of the Pd(001) surface.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.141-141
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• 2000

In situ surface magneto-optic Kerr effect(SMOKE), X-ray photoelectron spectroscopy(XPS) and low energy electron diffraction(LEED) were used to study magnetic and structural properties of ultrathin Fe films grown on the Pd(111) surface. The SMOKE measurement showed strong enhancement of ferromagnetism after proper annealing process. Simultaneous changes in morphology was checked by LEED and XPS. After room temperature Fe deposition. longitudinal magnetization appeared above a critical thickness between 2.0 and 2.5 monolayers. When annealed at 450K, 2.0 monolayer Fe film exhibited boty longitudinal and polar magnetizations while 3.0 and 5.5 monolayer films showed little changes. After annealing at 600K, both magnetizations were totally destroyed in 2.0 monolayer film, but longitudinal magnetization was enhanced in 3.0 monolayer film. In the case of 5.5 monolayer film, it was only after 660K annealing that the enhancement of the longitudinal magnetization was observed. It was concluded that the surface flatness and the amount of intermixing were critical in the development of surface magnetism of this system.

• Proceedings of the Korean Magnestics Society Conference
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• 2004.12a
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• pp.56-57
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• 2004

• Proceedings of the Korean Magnestics Society Conference
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• 2004.12a
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• pp.14-14
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• 2004

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.116.1-116.1
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• 2007