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arXiv · 1307.6690

Spectroscopic evidence for giant orbital moment and magnetic anisotropy induced by local distortions in alpha-CoV2O6

N. Hollmann·S. Agrestini·Z. Hu·Z. He·M. Schmidt·C. -Y. Kuo·M. Rotter·A. A. Nugroho·V. Sessi·A. Tanaka·N. B. Brookes·L. H. Tjeng
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Abstract

We present a combined experimental and theoretical study on the local magnetism of the Co ions in the spin-chain compound CoV2O6, which crystallizes in two different allotropic phases, alpha- and gamma-CoV2O6. Using x-ray magnetic circular dichroism, we have found a very large and a moderate orbital contribution to the magnetism in alpha- and gamma-CoV2O6, respectively. Full-multiplet calculations indicate that the differences in the magnetic behavior of alpha- and gamma-CoV2O6 phases originate from different local distortions of the CoO6 octahedra. In particular, the strong compression of the CoO6 octahedra in alpha-CoV2O6 lead to a strong mixture of t2g and eg orbitals which, via the local atomic Coulomb and exchange interactions, results in an exceptionally large orbital moment.

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N. Hollmann, S. Agrestini, Z. Hu, Z. He, M. Schmidt, C. -Y. Kuo, M. Rotter, A. A. Nugroho, V. Sessi, A. Tanaka, N. B. Brookes, L. H. Tjeng. 2013-07-25. Spectroscopic evidence for giant orbital moment and magnetic anisotropy induced by local distortions in alpha-CoV2O6. https://doi.org/10.1103/physrevb.89.201101

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