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
Spin–orbit coupled molecular quantum magnetism realized in inorganic solid
Sang-Youn Park,Seung-Hwan Do,Seung-Hwan Do,Kwang-Yong Choi,J.-H. Kang,Dong-Jin Jang,Burkhard Schmidt,Manuel Brando,Byoungkook Kim,Dohun Kim,Nicholas P. Butch,Seongsu Lee,Joonbum Park,Sungdae Ji +13 more
TL;DR: Inelastic neutron scattering results reveal that a large Dzyaloshinsky–Moriya interaction originating from strong spin–orbit coupling of Yb 4f is a key ingredient to explain magnetic excitations of the molecular magnet states.
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Effect of Gd substitution on the crystal structure and multiferroic properties of BiFeO3
V. A. Khomchenko,Vladimir V. Shvartsman,Pavel Borisov,W. Kleemann,Dmitry A. Kiselev,Igor Bdikin,Joaquim M. Vieira,Andrei L. Kholkin +7 more
TL;DR: In this paper, the crystal structure, magnetic and local ferroelectric properties of polycrystalline Bi 1− x Gd x FeO 3 ( x ǫ = 0.1, 0.2,0.3) samples were investigated at room temperature.
Journal ArticleDOI
Spectroscopic studies on two-iron ferredoxins.
R. H. Sands,W. R. Dunham +1 more
TL;DR: The application of magnetic resonance techniques to biological systems has permitted a detailed study of the nature of the active sites of many proteins that had not been possible previously, and the whole class of iron—sulphur proteins, the rubredoxins, are among them.
Journal ArticleDOI
Microscopic model and phase diagrams of the multiferroic perovskite manganites
TL;DR: In this article, the authors theoretically study the phase diagram of perovskite manganites by constructing a microscopic spin model, which includes not only the superexchange interaction but also the single-ion anisotropy (SIA) and the Dzyaloshinsky-Moriya interaction (DMI).
Journal ArticleDOI
Phase diagram and entanglement of the Ising model with Dzyaloshinskii-Moriya interaction
TL;DR: In this paper, the phase diagram and entanglement of the one-dimensional Ising model with Dzyaloshinskii-Moriya (DM) interaction were studied and the quantum renormalization-group approach was applied to get the stable fixed points, critical point, and the scaling of coupling constants.