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Strong spin-lattice coupling in multiferroic HoMnO$_{3}$: Thermal expansion anomalies and pressure effect

C. dela Cruz·F. Yen·B. Lorenz·Y. Q. Wang·Y. Y. Sun·M. M. Gospodinov·C. W. Chu
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Abstract

Evidence for a strong spin-lattice coupling in multiferroic HoMnO_3 is derived from thermal expansion measurements along a- and c-axis. The magnetoelastic effect results in sizable anomalies of the thermal expansivities at the antiferromagnetic (T_N) and the spin rotation (T_{SR}) transition temperatures as well as in a negative c-axis expansivity below room temperature. The coupling between magnetic orders and dielectric properties below T_N is explained by the lattice strain induced by the magnetoelastic effect. At T_{SR} various physical quantities show discontinuities that are thermodynamically consistent with a first order phase transition.

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C. dela Cruz, F. Yen, B. Lorenz, Y. Q. Wang, Y. Y. Sun, M. M. Gospodinov, C. W. Chu. 2005-01-25. Strong spin-lattice coupling in multiferroic HoMnO$_{3}$: Thermal expansion anomalies and pressure effect. https://doi.org/10.1103/physrevb.71.060407

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