Strain coupling in multiferroic phase transitions of samarium yttrium manganite Sm 0.6 Y 0.4 MnO 3

摘要: Sm1−xYxMnO3 (SYM x) is one of a class multiferroic manganites that has seen significant recent interest due to the intimate connection between cycloidal magnetic order and ferroelectricity in these materials. SYM shows sequential transitions paramagnetic, sinusoidally ordered antiferromagnetic cycloidally phases with decreasing temperature. As other members family, spin cycloid induces ferroelectricity, although whether there any elastic coupling involved this process not known. In work, resonant ultrasound spectroscopy (RUS) used examine stiffness dissipation 0.4 as are traversed. It found only very small signatures properties material, indicating weakness magnetoelastic (and electroelastic) coupling. The mechanical loss does show decrease upon cooling below TN1=∼50 K, freezing some mechanism near temperature where achieved. strain at related Eu1−xYxMnO3, examined from data published literature, low shear observed, along more volume effect. This correlates well observations RUS, peak frequencies sensitive effects than bulk effects. These results suggest weak may be general behavior perovskite-related manganites.