Soyoung Jekal

Surface-termination-dependent magnetism and strong perpendicular magnetocrystalline anisotropy of an FeRh(001) thin film

Magnetism of FeRh (001) films strongly depends on film thickness and surface terminations. While magnetic ground state of bulk FeRh is G-type antiferromagnetism, the Rh-terminated films exhibit ferromagnetism with strong perpendicular MCA whose energy +2.1 meV/

Electron beam-formed ferromagnetic defects on MoS2 surface along 1 T phase transition.

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Thickness effect on magnetocrystalline anisotropy of Co/Pd(111) films: A density functional study

is two orders of magnitude greater than 3

First Principles Calculations on Magnetism of CrPt3(001) Thin Films

d

First-principles Calculations on Magnetism of 1H/1T Boundary in Monolayer MoS 2

magnetic metals, where

Magnetism of Asymmetrically Terminated FeRh(001) Thin Films: A First-Principle Study

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Magnetocrystalline Anisotropy of d0-Magnetic Material NaN(001) Thin Films: A Density Functional Study.

is area of two-dimensional unit cell. While Goodenough-Kanamori-Anderson rule on the superexchange interaction is crucial in determining the magnetic ground phases of FeRh bulk and thin films, the magnetic phases are results of interplay and competition between three mechanisms - the superexchange interaction, the Zener direct-interaction, and magnetic energy gain.

First Principle Studies on Magnetism and Electronic Structure of Perovskite Structured CoFeX3(X = O, F, S, Cl)

1 T phase incorporation into 2H-MoS2 via an optimal electron irradiation leads to induce a weak ferromagnetic state at room temperature, together with the improved transport property. In addition to the 1T-like defects, the electron irradiation on the cleaved MoS2 surface forms the concentric circle-type defects that are caused by the 2 H/1 T phase transition and the vacancies of the nearby S atoms of the Mo atoms. The electron irradiation-reduced bandgap is promising in vanishing the Schottky barrier to attaining spintronics device. The simple method to control and improve the magnetic and electrical properties on the MoS2 surface provides suitable ways for the low-dimensional device applications.

Materials with large MCA and design principles of large MCA

In this study, we carried out first-principles calculations on magnetocrystalline anisotropy (MCA) of Co/Pd thin films by adopting two different systems of (i) n-Co/3-Pd and (ii) n-Pd/3-Co. In one system, we vary the thickness of Co layer, fixing the thickness of the Pd layer to 3-monolayers, and in the other system vice versa. MCA is mainly governed by the surface and interface Co atoms, while contributions from other Co atoms are smaller. MCA energy (EMCA) of the Co/Pd thin film shows oscillatory behavior with the thickness of the Co layer, but is insensitive to the thickness of the Pd layer. In particular, the n-Co/3-Pd films of n = 2, 4, and 6 exhibit strong perpendicular MCA of about 1 meV. Our results suggest that controlling the thickness of the Co layer in Co/Pd (111) is crucial in achieving strong perpendicular MCA.

Magnetism and magnetocrystalline anisotropy of FeRh(001) thin films

Recent study shows that ordered alloy of L12 XPt3 (M = V, Cr, Mn, Co, and Fe) exhibits various magnetic phases such as ferromagnetic-to-antiferromagnetic transition at the MnPt3 surface. Moreover, it has been argued that CrPt3, in particular, possess large magnetocrystalline anisotropy and Kerr rotation with possible violation of Hund’s rule. As such, we extend our work to thickness dependence of the magnetic structure of CrPt3 thin film using density functional theory. Magnetic ground state of the bulk CrPt3 turns out to be ferromagnetic (FM), where other magnetic phases such as A-type (A-AF), C-type (C-AF), and G-type antiferromagnetic (GAF) state have higher total energies than FM by 0.517, 0.591, and 0.183 eV, respectively, and magnetic moments of Cr in bulk are respectively 2.807 (FM), 2.805 (A-AF), 2.794 (C-AF) and 2.869 μB (G-AF). We extend our study to CrPt3(001) thin films with CrPtand Pt-termination. The thickness and surface-termination dependences of magnetism are investigated for 3-9 monolayers (ML), where different magnetic phases from bulk emerge: C-AF for CrPt-terminated 3 ML and G-AF for Pt-terminated 5 ML have energy difference relative to FM by 8 and 54 meV, respectively. Furthermore, thicknessand surface-termination-dependent magnetocrystalline anisotropies of the CrPt3(001) films are discussed.