Electric field effect of relaxor ferroelectric (1 − x)Pb(Mg1/3Nb2/3)O3–xPbTiO3 crystals near morphotropic phase boundary composition probed by Brillouin scattering

Abstract The relaxor ferroelectric (1 − x )Pb(Mg 1/3 Nb 2/3 )O 3 – x PbTiO 3 ( x = 0.30, PMN–30PT) single crystal was studied under the zero field and the externally applied dc electric field by using micro-Brillouin scattering and dielectric spectroscopies over a wide temperature range of 303–773 K. The noticeable thermal hysteresis of longitudinal acoustic (LA) shift (ν B ) was observed between zero field heating and zero field cooling processes. Under the electric field of 0.5 kV/cm along the [001] axis, the LA mode splitting was observed in ν B due to the coexistence of ferroelectric macrodomain and nanodomain states caused by the random field, and in dielectric measurements the monoclinic (M) and tetragonal phases were appeared between rhombohedral and cubic phases. The LA mode splitting and M phase disappeared under the field of 1.0 kV/cm. The electric field dependence of LA velocity was studied at 304 K. The critical end point of the PMN–30PT single crystal was investigated.