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Orbital order in the low-dimensional quantum spin system TiOCl probed by ESR

V. Kataev·J. Baier·A. Moeller·L. Jongen·G. Meyer·A. Freimuth
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Abstract

We present electron spin resonance data of Ti$^{3+}$ (3$d^1$) ions in single crystals of the novel layered quantum spin magnet TiOCl. The analysis of the g tensor yields direct evidence that the d_{xy} orbital from the t_{2g} set is predominantly occupied and owing to the occurrence of orbital order a linear spin chain forms along the crystallographic b axis. This result corroborates recent theoretical LDA+U calculations of the band structure. The temperature dependence of the parameters of the resonance signal suggests a strong coupling between spin and lattice degrees of freedom and gives evidence for a transition to a nonmagnetic ground state at 67 K.

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V. Kataev, J. Baier, A. Moeller, L. Jongen, G. Meyer, A. Freimuth. 2003-09-24. Orbital order in the low-dimensional quantum spin system TiOCl probed by ESR. https://doi.org/10.1103/physrevb.68.140405

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