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arXiv:1604.03333 · Physical review. B./Physical review. B

Hybridization and spin-orbit coupling effects in the quasi-one-dimensional spin- 1 2 magnet Ba 3 Cu 3 Sc 4 O 12

Danis I. Badrtdinov, О. С. Волкова, Alexander A. Tsirlin, Igor V. Solovyev, Alexander N. Vasiliev, Vladimir V. Mazurenko

Published Aug 31, 2016• 11 citations
arXivHTMLPDF

Abstract

We study electronic and magnetic properties of the quasi-one-dimensional spin-$\frac{1}{2}$ magnet ${\mathrm{Ba}}_{3}{\mathrm{Cu}}_{3}{\mathrm{Sc}}_{4}{\mathrm{O}}_{12}$ with a distinct orthogonal connectivity of ${\mathrm{CuO}}_{4}$ plaquettes. An effective low-energy model taking into account spin-orbit coupling was constructed by means of first-principles calculations. On this basis, a complete microscopic magnetic model of ${\mathrm{Ba}}_{3}{\mathrm{Cu}}_{3}{\mathrm{Sc}}_{4}{\mathrm{O}}_{12}$, including symmetric and antisymmetric anisotropic exchange interactions, is derived. The anisotropic exchanges are obtained from a distinct first-principles numerical scheme combining, on one hand, the local density approximation taking into account spin-orbit coupling, and, on the other hand, a projection procedure along with the microscopic theory by Moriya [Phys. Rev. 120, 91 (1960)]. The resulting tensors of the symmetric anisotropy favor collinear magnetic order along the structural chains with the leading ferromagnetic coupling ${J}_{1}\ensuremath{\simeq}\ensuremath{-}9.88$ meV. The interchain interactions ${J}_{8}\ensuremath{\simeq}0.21$ and ${J}_{5}\ensuremath{\simeq}0.093$ meV are antiferromagnetic. Quantum Monte Carlo simulations demonstrate that the proposed model reproduces the experimental Neel temperature, magnetization, and magnetic susceptibility data. The modeling of neutron-diffraction data reveals an important role of the covalent Cu-O bonding in ${\mathrm{Ba}}_{3}{\mathrm{Cu}}_{3}{\mathrm{Sc}}_{4}{\mathrm{O}}_{12}$.

DOI
10.1103/physrevb.94.054435

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