Evidence for a strong spin-lattice coupling in multiferroic HoMnO 3 is derived from thermal expansion measurements along the a and c axes. 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.
|期刊||Physical Review B - Condensed Matter and Materials Physics|
|出版狀態||Published - 2005 2月|
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