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

• Published in: Advanced functional materials 2022-06, Vol.32 (25), p.n/a
• Main Authors: Li, Qian, Liu, Yangbin, Liu, Jinfeng, Song, Kexin, Guo, Haisheng, Li, Fei, Xu, Zhuo
• Format: Article
• Language: English
• Subjects: Coefficient of variation; Crystal growth; Crystals; Electron probes; Ferroelectricity; Heterogeneity; Lead titanates; Materials science; Nd‐dopants; Neodymium; Phase transitions; Piezoelectric transducers; Piezoelectricity; relaxor ferroelectric crystals; Relaxors; Single crystals; Transition temperature
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202201719

Relaxor‐PbTiO3 crystals exhibit excellent piezoelectric properties (d33 > 2000 pC N−1 and k33 > 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)O3‐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 °C, which indicates that Nd‐doped PMN‐PT crystal can be a promising candidate for the design of advanced piezoelectric transducers. By using A‐site rare‐earth dopants, the authors offset the variations of ferroelectric phase and electromechanical properties along the crystal growth direction induced by the segregation of B‐site cations. The Nd‐doped Pb(Mg1/3Nb2/3)O3‐PbTiO3 crystals exhibit ultrahigh piezoelectric properties with relatively high phase transition temperature. These crystals are promising candidates for advanced piezoelectric applications.