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Exploring the high pressure phase diagram of La$_{1-x}$Ca$_{x}$MnO$_{3}$

A. Sani·C. Meneghini·S. Mobilio·Sugata Ray·D. D. Sarma·J. A. Alonso
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Abstract

The structure of La$_{1-x}$Ca$_{x}$MnO$_{3}$ solid solutions (x=0, 0.25, 0.50, 0.67, 1) under high pressure (up to 40-45 GPa) has been investigated by synchrotron X-ray powder diffraction (XRD) in order to characterize their volume \emph{vs.} pressure (P-V) equation of state. All the members of the solid solution, except the extreme compounds: LaMnO$_3$ and CaMnO$_{3}$, present low pressure orthorhombic P$nma$ phase evolving toward an high pressure tetragonal (I$4/mcm$) symmetry. The details of this transition are related to the Ca doping: on increasing the Ca content, the critical pressure of the transition decreases, but the energetic cost of the transition increases. This study depicts a peculiar evolution of structural distortions as a function of pressure and concentration.

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A. Sani, C. Meneghini, S. Mobilio, Sugata Ray, D. D. Sarma, J. A. Alonso. 2003-04-17. Exploring the high pressure phase diagram of La$_{1-x}$Ca$_{x}$MnO$_{3}$. https://arxiv.org/abs/cond-mat/0304394

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