Irreversible alterations of ferroelectric domain structure in paramagnetic rare earth molybdates induced by a magnetic field

The effect of a magnetic field on the ferroelectric domain structure of single crystal samples of the metastable orthorhombic ferroelectric ferroelastic β′-phase of Sm2(MoO4)3, Gd2(MoO4)3, Tb2(MoO4)3, and TbGd(MoO4)3 was investigated at 78 K in pulsed magnetic fields up to 100 kOe. It was shown that a magnetic field of certain orientation may change a ferroelectric domain structure in Tb2(MoO4)3 and TbGd(MoO4)3 that was accompanied by large changes of the electric polarization of the sample under investigation. The effect is explained by large magnetostrictive deformations. The prediction is made that there must be a positive longitudinal magnetostriction in a magnetic field applied along the [100] crystallographic axis and a negative transverse magnetostriction in the (001) plane in a magnetic field applied along the [100] crystallographic axis in Tb2(MoO4)3 and in TbGd(MoO4)3 β′-phases at 78 K and at a magnetic field strength of about 100 kOe.