Morphotropic phase boundaries of (1−x)Pb(Zn_1/3Nb_2/3)O₃–xPbTiO₃ probed by Raman spectroscopy at high temperature

Abstract

Morphotropic phase boundaries (MPBs) in relaxor Pb(Zn 1/3 Nb 2/3 )O 3 -ferroelectric PbTiO 3 systems were investigated by means of angle-resolved polarized Raman spectroscopy at 800 K in the paraelectric phase. The features of the spectra represented by contour maps were extracted through the multivariate curve resolution (MCR) method, rendering the comparison among the data with six compositions more accurate and convenient. The result indicates that the structure becomes unstable at x = 0.07, which is slightly smaller than the MPB occurring at x = 0.09. The additional analysis using the MCR method to investigate the x dependence of the extracted Raman spectra shows anomalies at the MPB. The information related to the MPB near room temperature could be extracted through Raman spectroscopy even in a simple high-temperature paraelectric phase.

Temperature-gradient investigation of phase transitions in ferroelectrics using cooling and heating stage

“…Raman scattering data were acquired using our system, which comprises a polarization rotation system installed in a microscope. 25,[28][29][30][31][32] A BaTiO 3 crystal was placed in the cooling and heating stage (with a quartz glass window) on an XYZ mapping stage installed in the microscope. Using a 10x objective lens, the focus was about 10 μm in diameter on the sample.…”

Ferroelectric polarization of tetragonal BiFeO3—an approach from DFT calculations for BiFeO3–BaTiO3 superlattices—

“…[4][5][6][7][8][9] For Pb(Mg, Nb)O 3 -PbTiO 3 and Pb(Zn, Nb)O 3 -PbTiO 3 with extraordinary high piezoelectric properties, their MPBs provide a bridging phase in monoclinic symmetry 3,[10][11][12] that enables a rotation of the spontaneous polarization (P s ) vector. 10,[13][14][15][16][17][18][19][20][21][22] To establish an MBP similar to the PZT system, various lead-free solid solution systems have been investigated and composition-driven variations of crystal structure and properties have been studied. Since the discovery of (K, Na)NbO 3 -based ceramics with properties comparable to PZT, 23) (K, Na)NbO 3 [24][25][26][27][28][29][30] and its related Nb-based materials [31][32][33][34][35][36] have intensively studied with the aim of developing lead-free piezoelectric devices.…”