Behavior of atomic displacements and Mn-Mn coupling in YMnO3 single crystal

Multiferroic materials are one kind of material which couples two or more of the properties of (anti) ferromagnetism, ferroelectricity, and ferroelasticity together. The coupling between the magnetic and ferroelectric order parameters may lead to the magnetoelectric effect, in which the magnetization may be controlled by an electric field, or vice versa. Multiferroic materials are currently one of the important subject of intensive investigations both because of the interesting physics involved and their potential applications in data storage, spintronics, and sensors. Among the multiferroic materials, YMnO₃ manganites have attracted a great deal of attention due to the significant coupling between the magnetic and electric order parameters with the highest critical temperature both in antiferromagnetism and ferroelectroicity due to evidences of the strong interplay between the magnetic and ferroelectric order. The dielectric constant reveals clearly an anomaly near the Neel temperature (T_N). On the other hand large atomic displacements have also been observed near T_N which may indicate a strong magnetoelastic coupling. In this way high quality single crystal is essential for detailed study on the properties for YMnO₃.