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arXiv · 2107.07219

Crystal growth, characterization and phase transition of PbCuTe$_2$O$_6$

A. R. N. Hanna·A. T. M. N. Islam·R. Feyerherm·K. Siemensmeyer·K. Karmakar·S. Chillal·B. Lake
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Abstract

Single crystals of the three-dimensional frustrated magnet and spin liquid candidate compound PbCuTe$_2$O$_6$ were grown using both the Travelling Solvent Floating Zone (TSFZ) and the Top-Seeded Solution Growth (TSSG) techniques. The growth conditions were optimized by investigating the thermal properties. The quality of the crystals was checked by polarized optical microscopy, X-ray Laue and X-ray powder diffraction, and compared to the polycrystalline samples. Excellent quality crystals were obtained by the TSSG method. Magnetic measurements of these crystals revealed a small anisotropy for different crystallographic directions in comparison with the previously reported data. The heat capacity of both single crystal and powder samples reveal a transition anomaly around 1 K. Curiously the position and magnitude of the transition are strongly dependent on the crystallite size and it is almost entirely absent for the smallest crystallites. A structural transition is suggested which accompanies the reported ferroelectric transition, and a scenario whereby it becomes energetically unfavourable in small crystallites is proposed.

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A. R. N. Hanna, A. T. M. N. Islam, R. Feyerherm, K. Siemensmeyer, K. Karmakar, S. Chillal, B. Lake. 2021-07-15. Crystal growth, characterization and phase transition of PbCuTe$_2$O$_6$. https://doi.org/10.1103/physrevmaterials.5.113401

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