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arXiv · 1010.0786

Two pressure-induced structural phase transitions in TiOCl

J. Ebad-Allah·A. Schönleber·S. van Smaalen·M. Hanfland·M. Klemm·S. Horn·S. Glawion·M. Sing·R. Claessen·C. A. Kuntscher
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Abstract

We studied the crystal structure of TiOCl up to pressures of $p$=25~GPa at room temperature by x-ray powder diffraction measurements. Two pressure-induced structural phase transitions are observed: At $p_{c1}$$\approx$15~GPa emerges an 2$a$$\times$2$b$$\times$$c$ superstructure with $b$-axis unique monoclinic symmetry (space group P2$_1$/$m$). At $p_{c2}$$\approx$22~GPa all lattice parameters of the monoclinic phase show a pronounced anomaly. A fraction of the sample persists in the ambient orthorhombic phase (space group $Pmmn$) over the whole pressure range.

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J. Ebad-Allah, A. Schönleber, S. van Smaalen, M. Hanfland, M. Klemm, S. Horn, S. Glawion, M. Sing, R. Claessen, C. A. Kuntscher. 2010-10-05. Two pressure-induced structural phase transitions in TiOCl. https://doi.org/10.1103/physrevb.82.134117

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