MPB design and crystal growth of PMN–PT–PZ relaxor ferroelectrics

• Published in: Journal of crystal growth 2011-03, Vol.318 (1), p.851-855
• Main Authors: Li, Qiang, Zhang, Yiling, Xia, Zhiguo, Chu, Xiangcheng
• Format: Article
• Language: English
• Subjects: A1. MBP; A1. Structural phase transition; B1. PMN–PT–PZ; B2. Relaxor ferroelectric single crystal; B2. TR−T; Composition and phase identification; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Crystal growth; Design engineering; Exact sciences and technology; Ferroelectric materials; General equipment and techniques; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Magnesium; Materials science; Methods of crystal growth; physics of crystal growth; Phase boundaries; Phase transformations; Physics; Piezoelectricity; Relaxors; Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2010.10.208

Rhombohedral–tetragonal ferroelectric structural phase transition temperature (TR−T), far below the Curie temperature (Tc) in lead magnesium niobate–lead titanate (PMN–PT) relaxor ferroelectric single crystal, heavily restricts its further applications either as a sensor or transducer. To overcome this shortcoming, lead zirconate (PZ) was introduced into the PMN–PT pseudo-binary system to increase TR−T via the morphotropic phase boundary (MPB) composition design and optimization. According to the PMN–PT–PZ pseudo-ternary phase diagram, various compositions have been selected to discuss the relations between their phase structural transition and piezoelectric properties in the PMN–PT–PZ pseudo-ternary system. X-ray diffraction (XRD) investigation indicates clearly that PMN–PT–PZ ceramics with MPB compositions experience a typical structural phase transition process from rhombohedral phase to tetragonal phase. Remnant polarization (Pr=33.4μC/cm2) and piezoelectric coefficient (d33=1050pC/N) were obtained at the (001) cut PMN–PT–PZ single crystal. TR−T was increased up to 120°C by measuring its dependence of dielectric constant on temperature.