Journal Article

PreJuSER-443

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Effect of high pressure on competing exchange couplings in Li2VOSiO4

Pavarini, E.FZJ* ; Tarantino, S. C. ; Boffa Ballaran, T. ; Zema, M. ; Ghigna, P. ; Carretta, P.

2008
APS College Park, Md.

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Please use a persistent id in citations: http://hdl.handle.net/2128/10797  doi:10.1103/PhysRevB.77.014425

Abstract: We report x-ray diffraction measurements on Li2VOSiO4 single crystals under pressures up to 7.6 GPa. The structure evolution under high pressure evidences a strongly anisotropic compressibility and a significant contraction of Li-O bonds. The corresponding evolution of the electronic structure was calculated ab initio. Using first-principles Wannier functions, we constructed, for several pressures, a (material-specific) low-energy one-band Hubbard model for the half-filled V xy bands. We found that the ratio between the next-nearest neighbor and nearest neighbor hopping integral, t(2)/t(1), decreases by about 23% when the pressure increases from 0 to 7.6 GPa. By means of standard superexchange theory, we estimated a corresponding decrease of about 40% in the ratio J(2)/J(1) between the next-nearest neighbor and nearest neighbor magnetic coupling. This suggests that one could possibly tune the ground state of this frustrated two-dimensional antiferromagnet from collinear to disordered by applying high pressures.

Keyword(s): J

Note: Record converted from VDB: 12.11.2012

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Contributing Institute(s):

1. Theorie der Strukturbildung (IFF-3)

Research Program(s):

1. Kondensierte Materie (P54)

Appears in the scientific report 2008

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Database coverage:
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