Absence of a spiral magnetic order in Li2CuO2 containing one-dimensional CuO2 ribbon chains

[摘要] On the basis of first-principles density functional theory electronic structure calculations as well as classical spin analysis, we explored why the magnetic oxide Li2CuO2, consisting of CuO2 ribbon chains made up of edge-sharing CuO4 squares, does not exhibit a spiral-magnetic order. Our work shows that, due to the next-nearest-neighbor interchain interactions, the observed collinear magnetic structure becomes only slightly less stable than the spin-spiral ground state and many states become nearly degenerate in energy with the observed collinear structure. This suggests that the collinear magnetic structure of Li2CuO2 is a consequence of order by disorder induced by next-nearest-neighbor interchain interactions.

[发布日期] 2007-12-01

[关键词] EXCHANGE INTERACTIONS;SPIN-EXCHANGE;DISORDER