Mn-doped Pb(In1/2Nb1/2)O3-Pb(Mg2/3Nb1/3)O3-PbTiO3 (Mn:PIN-PMN-PT) single crystals, which exhibit improved phase transition temperatures and coercive field properties compared to Pb(In1/2 Nb1/2)O3-Pb(Mg2/3Nb1/3)O3-PbTiO3 (PIN-PMNPT) single crystals, are expected to be utilized in high-power acoustic transducers. Bridgeman method, growing single crystals along the axial direction from melt, is most widely used method for single crystal growth with large size and high quality. However, single crystal boules grown by the Bridgeman method demonstrate a PT compositional variation, giving rise a distribution of crystal structure and material properties along the growing axis. To employ piezoelectric single crystals grown by the Bridgeman method for acoustic transducers, it is essential to investigate their overall property distribution. In this study, the compositional distribution and property variation of Mn:PIN-PMN-PT single crystals grown by the Bridgeman method was investigated. Measured compositional distribution of PT was from 29% to 32.5% in the Rhombohedral crystal region of the boule. Two types of specimen, [011]-poled Mn:PIN-PMN-29PT and Mn:PIN-PMN-32PT single crystals, were fabricated and tested to obtain full property variation at both ends of the Rhombohedral crystal region. The properties related to the 32 directional vibration mode and the properties related to high-power driving were measured to confirm the overall distribution of properties by composition.
