Journal ArticleDOI
Anisotropic Superexchange Interaction and Weak Ferromagnetism
TLDR
In this paper, the Anderson theory of superexchange was extended to include spin-orbit coupling and the antisymmetric spin coupling suggested by Dzialoshinski from purely symmetry grounds and the symmetric pseudodipolar interaction were derived.Abstract:
A theory of anisotropic superexchange interaction is developed by extending the Anderson theory of superexchange to include spin-orbit coupling. The antisymmetric spin coupling suggested by Dzialoshinski from purely symmetry grounds and the symmetric pseudodipolar interaction are derived. Their orders of magnitudes are estimated to be ($\frac{\ensuremath{\Delta}g}{g}$) and ${(\frac{\ensuremath{\Delta}g}{g})}^{2}$ times the isotropic superexchange energy, respectively. Higher order spin couplings are also discussed. As an example of antisymmetric spin coupling the case of Cu${\mathrm{Cl}}_{2}$\ifmmode\cdot\else\textperiodcentered\fi{}2${\mathrm{H}}_{2}$O is illustrated. In Cu${\mathrm{Cl}}_{2}$\ifmmode\cdot\else\textperiodcentered\fi{}2${\mathrm{H}}_{2}$O, a spin arrangement which is different from one accepted so far is proposed. This antisymmetric interaction is shown to be responsible for weak ferromagnetism in $\ensuremath{\alpha}$-${\mathrm{Fe}}_{2}$${\mathrm{O}}_{3}$, MnC${\mathrm{O}}_{3}$, and Cr${\mathrm{F}}_{3}$. The paramagnetic susceptibility perpendicular to the trigonal axis is expected to increase very sharply near the N\'eel temperature as the temperature is lowered, as was actually observed in Cr${\mathrm{F}}_{3}$.read more
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Journal ArticleDOI
Oxidation dependence of the Dzyaloshinskii-Moriya interaction in Pt /Co /M O x trilayers (M =Al or Gd)
TL;DR: In this paper, the authors studied the interfacial Dzyaloshinskii-Moriya interaction (DMI) in trilayers in which the degree of oxidation of the top Co interface is varied.
Journal ArticleDOI
A skyrmion-based spin-torque nano-oscillator with enhanced edge
Youhua Feng,Jing Xia,Lei Qiu,Xinran Cai,Xinran Cai,Laichuan Shen,F.J. Morvan,Xichao Zhang,Yan Zhou,Guoping Zhao,Guoping Zhao,Guoping Zhao +11 more
TL;DR: In this article, a modified nanodisk structure, in which a skyrmion can be driven by a large current density, is proposed, and numerical simulations demonstrate that when the edge of a ferromagnetic nanodisc has enhanced perpendicular magnetic anisotropy, the upper threshold of the skyrmmion oscillation frequency can be increased by 75% compared to the original structure without enhanced edge.
Journal ArticleDOI
On the nature of the reversibility of hydration-dehydration on the crystal structure and magnetism of the ferrimagnet [MnII(enH)(H2O)][CrIII(CN)6].H2O.
TL;DR: Thermogravimetric analyses indicate that the crystallinity deteriorates upon hydration-dehydration cycling, with persistence toward the amorphous phase, as also seen by magnetization measurements.
Journal ArticleDOI
Observation of Hydrogen-Induced Dzyaloshinskii-Moriya Interaction and Reversible Switching of Magnetic Chirality
Gong Chen,Gong Chen,MacCallum Robertson,Markus Hoffmann,Colin Ophus,André Luis Fernandes Cauduro,Roberto Lo Conte,Roberto Lo Conte,Haifeng Ding,Roland Wiesendanger,Stefan Blügel,Andreas K. Schmid,Kai Liu,Kai Liu +13 more
TL;DR: In this paper, Chen et al. reported direct observation of induced DMI by chemisorption of the lightest element, hydrogen, on a ferromagnetic layer at room temperature, which was supported by density functional theory calculations.
Journal ArticleDOI
Synthesis and Characterization of BiFeO3 Thin Films for Multiferroic Applications by Radical Enhanced Atomic Layer Deposition
TL;DR: A radicalenhanced atomic layer deposition (RE-ALD) process is described in this paper for the synthesis of BiFeO3, and the films have properties comparable to those of films grown by other methods.