Overpoling-induced property degradation in Pb (Mg 1/3Nb 2/3)O 3-PbTiO 3 single crystals of near-morphotropic phase boundary compositions

Abstract

Overpoling phenomenon has been observed in flux-grown Pb (Mg13 Nb23) O3 - (31-32) %PbTi O3 single crystals when poled above 0.4 kVmm at room temperature. This leads to increased property variations at intermediate poling fields (0.6-0.8 kVmm) and to the degradation of piezoelectric properties at high poling fields (≤1.0 kVmm). In comparison, both PMN-28%PT and PMN-30%PT crystal compositions are resistant to overpoling, of which PMN-30%PT exhibits superior dielectric and piezoelectric properties with KT ≈7500-9000, d33 ≈2200-2500 pCN, and d31 ≈1100-1400 pCN. The electromechanical coupling factors (k33 =0.90-0.94; k31 =0.48-0.55, and kt =0.58-0.62) are relatively insensitive to the poling field and crystal composition. © 2005 American Institute of Physics.