Ferroelastic domain structure and phase transition in single-crystalline [PbZn1/3Nb2/3O3]1-x[PbTiO3]x observed via in situ x-ray microbeam

• Published in: Journal of the European Ceramic Society Vol. 38; no. 4; pp. 1488 - 1497
• Main Authors: Li, Tao, Du, Zehui, Tamura, Nobumichi, Ye, Mao, Inguva, Saikumar, Lu, Wei, Zeng, Xierong, Ke, Shanming, Huang, Haitao
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.04.2018; Elsevier
• Subjects: MATERIALS SCIENCE
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2017.11.021

(1-x)Pb(Zn1/3Nb2/3)O3-xPbTiO3 ((1-x)PZN-xPT in short) is one of the most important piezoelectric materials. In this work, we extensively investigated (1-x)PZN-xPT (x=0.07–0.11) ferroelectric single crystals using in-situ synchrotron μXRD, complemented by TEM and PFM, to correlate microstructures with phase transitions. The results reveal that (i) at 25°C, the equilibrium state of (1-x)PZN-xPT is a metastable orthorhombic phase for x=0.07 and 0.08, while it shows coexistence of orthorhombic and tetragonal phases for x=0.09 and x=0.11, with all ferroelectric phases accompanied by ferroelastic domains; (ii) upon heating, the phase transformation in x=0.07 is Orthorhombic→Monoclinic→Tetragonal→Cubic. The coexistence of ferroelectric tetragonal and paraelectric cubic phases was in-situ observed in x=0.08 above Curie temperature (TC), and (iii) phase transition can be explained by the evolution of the ferroelectric and ferroelastic domains. These results disclose that (1-x)PZN-xPT are in an unstable regime, which is possible factor for its anomalous dielectric response and high piezoelectric coefficient.