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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Large Spin Hall Magnetoresistance in Antiferromagnetic α − Fe 2 O 3 / Pt Heterostructures
Johanna Fischer,Matthias Althammer,N. Vlietstra,Hans Huebl,Sebastian T. B. Goennenwein,Rudolf Gross,Stephan Geprägs,Matthias Opel +7 more
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J. N. McElearney,S. Merchant +1 more
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Nanomagnonics with artificial spin ice
TL;DR: In this article, the authors review experimental and theoretical works on the resonant excitations in the GHz frequency range in artificial spin ice and discuss both the theoretical formulation and experimental methods to characterize the dynamics in the nanomagnetic arrays.
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Synthesis of Ni-substituted Bi7Fe3Ti3O21 ceramics and their superior room temperature multiferroic properties
Shujie Sun,Yihan Ling,Ranran Peng,Min Liu,Xiangyu Mao,Chen Xiaobing,Randy Knize,Yalin Lu,Yalin Lu +8 more
TL;DR: In this article, layer-structured bismuth complex oxides (BFNT) were synthesized using a low-temperature combustion synthesis method and X-ray diffraction patterns and high-resolution transmission electron microscopy analysis indicated that the samples presented a six-layer Aurivillius structure.
Journal ArticleDOI
Giant exchange interaction in mixed lanthanides.
TL;DR: The microscopic mechanism governing the unusual exchange interaction in these compounds is revealed here by combining detailed modeling with density-functional theory and ab initio calculations, finding it to be basically kinetic and highly complex, involving non-negligible contributions up to seventh power of total angular momentum of each lanthanide site.