Overpoling resistance of [011]-poled Pb(Mg_(1/3)Nb_(2/3))O_3-PbTiO_3 single crystals

摘要

[011]-poled flux-grown Pb(Mg_(1/3)Nb_(2/3))O_3-PbTiO_3 (PMN-32%PT) single crystals are susceptible to overpoling at 0.4 kV/mm and higher fields, leading to degraded properties. This has been linked to the presence of an appreciable amount of the orthorhombic phase induced by the high poling fields. In contrast, flux-grown PMN-30%PT and PMN-31%PT single crystals show no signs of overpoling up to 2.0 kV/mm, both of which remain predominantly rhombohedral with a small amount of induced orthorhombic phase. Among the three compositions examined, flux-grown PMN-30%PT single crystal gives the best [011]-poled properties, with K~T= 5500-6000, d_(31) = 2100-2600 pC/N, and k_(31) =0.90-0.94. The present work further shows that, for a given crystal composition, flux-grown PMN-PT single crystals exhibit superior overpoling resistance to their melt-grown counterparts.