Antiferromagnetic S=1/2 Spin Chain Driven by p-Orbital Ordering in CsO2

Syarif Riyadi, Baomin Zhang, Robert A. de Groot, Antonio Caretta, Paul H. M. van Loosdrecht, Thomas T.M. Palstra, Graeme R. Blake

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26 Citations (Scopus)
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We demonstrate, using a combination of experiment and density functional theory, that orbital ordering drives the formation of a one-dimensional (1D) S=1/2 antiferromagnetic spin chain in the 3D rocksalt structure of cesium superoxide (CsO2
). The magnetic superoxide anion (O2) exhibits degeneracy of its 2p-derived molecular orbitals, which is lifted by a structural distortion on cooling. A spin chain is then formed by zigzag ordering of the half-filled superoxide orbitals, promoting a superexchange pathway mediated by the pz orbitals of Cs+ along only one crystal direction. This scenario is analogous to the 3d-orbital-driven spin chain found in the perovskite KCuF3 and is the first example of an inorganic quantum spin system with unpaired p electrons.
Original languageEnglish
Article number217206
JournalPhysical review letters
Issue number21
Publication statusPublished - 25 May 2012
Externally publishedYes


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