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arXiv · 0806.0230

Enhanced dimerization of TiOCl under pressure: spin-Peierls - to - Peierls transition

S. Blanco-Canosa·F. Rivadulla·A. Pineiro·V. Pardo·D. Baldomir·D. I. Khomskii·M. M. Abd-Elmeguid·M. A. Lopez-Quintela·J. Rivas
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Abstract

We report high-pressure x-ray diffraction and magnetization measurements combined with ab-initio calculations to demonstrate that the high-pressure optical and transport transitions recently reported in TiOCl, correspond in fact to an enhanced Ti3+-Ti3+ dimerization existing already at room temperature. Our results confirm the formation of a metal-metal bond between Ti3+ ions along the b-axis of TiOCl, accompanied by a strong reduction of the electronic gap. The evolution of the dimerization with pressure suggests a crossover from the spin-Peierls to a conventional Peierls situation at high pressures.

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S. Blanco-Canosa, F. Rivadulla, A. Pineiro, V. Pardo, D. Baldomir, D. I. Khomskii, M. M. Abd-Elmeguid, M. A. Lopez-Quintela, J. Rivas. 2008-06-02. Enhanced dimerization of TiOCl under pressure: spin-Peierls - to - Peierls transition. https://doi.org/10.1103/physrevlett.102.056406

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