Characterization of Mn-Doped PIN-PMN-PT Single Crystal Grown by Continuous-Feeding Bridgman Method

Mn-doped Pb(In1/2Nb1/2)O-3-Pb(Mg1/3Nb2/3)O-3-PbTiO3 (Mn:PIN-PMN-PT) single crystals are attractive piezoelectric materials owing to their high mechanical quality factor. However, the single crystal boules grown by the conventional Bridgman method show compositional variation along the growth direction. In particular, the Mn content exhibits large variation due to its severe segregation. To improve the compositional uniformity, we applied the continuous-feeding Bridgman method to the growth of a Mn:PIN-PMN-PT single crystal boule. Then, the composition and property distributions of the boule along the growth direction were evaluated. The results showed that excellent composition and property uniformity were carried out over 80mm in boule length. The ranges of the electromechanical coupling coefficient (k(33)) and the piezoelectric coefficient (d(33)) were 0.931-0.934 and 1352-1517 pC/N, respectively. The ranges of the mechanical quality factor (Qm(31)) and the depolarization field (E-d) were 417-535 and 785-859 V/mm, respectively. The Qm(31) and the E-d values were higher than those of the non-doped PIN-PMN-PT single crystals. The continuous-feeding Bridgman method is therefore an effective technique for improving the uniformity of the Mn content. As a result, the Mn:PIN-PMN-PT single crystal grown by the continuous-feeding Bridgman method possesses excellent property uniformity with characteristics suitable for high power piezoelectric applications.