Enhanced Piezoelectric Properties and Improved Property Uniformity in Nd-Doped PMN-PT Relaxor Ferroelectric Single Crystals

Relaxor-PbTiO3 crystals exhibit excellent piezoelectric properties (d(33) > 2000 pC N-1 and k(33) > 90%) and thus attractes widespread attention in the past two decades. However, the inevitable segregation of components during the crystal growth results in relatively low-performance consistency of Pb(Mg1/3Nb2/3)O-3-PbTiO3 (PMN-PT) crystals, which seriously affects their practical applications. In this work, Nd3+ as A-site substitution is introduced to improve the uniformity of electromechanical performance of PMN-PT crystal. The results show that the crystal exhibits a high piezoelectric coefficient of 3000 pC N-1 in rhombohedral phase with a variation of 36%. The electron probe X-ray microanalyzer indicates that the opposite separation characteristics of Nd3+ and Ti4+ lead to improved uniformity of piezoelectric performance along the crystal boule. The giant piezoelectricity in Nd-doped PMN-PT is attributed to the enhanced local structural heterogeneity introduced by doping Nd. Furthermore, the Nd-doped PMN-PT crystal shows the rhombohedral-tetragonal phase transition temperature in the range of 74-87 degrees C, which indicates that Nd-doped PMN-PT crystal can be a promising candidate for the design of advanced piezoelectric transducers.