A Strain-Driven Morphotropic Phase Boundary in BiFeO(3)

作者：Zeches R J^*; Rossell M D; Zhang J X; Hatt A J; He Q; Yang C H; Kumar A; Wang C H; Melville A; Adamo C; Sheng G; Chu Y H; Ihlefeld J F; Erni R; Ederer C; Gopalan V; Chen L Q; Schlom D G; Spaldin N A; Martin L W; Ramesh R

来源：Science, 2009, 326(5955): 977-980.

DOI：10.1126/science.1177046

Piezoelectric materials, which convert mechanical to electrical energy and vice versa, are typically characterized by the intimate coexistence of two phases across a morphotropic phase boundary. Electrically switching one to the other yields large electromechanical coupling coefficients. Driven by global environmental concerns, there is currently a strong push to discover practical lead-free piezoelectrics for device engineering. Using a combination of epitaxial growth techniques in conjunction with theoretical approaches, we show the formation of a morphotropic phase boundary through epitaxial constraint in lead-free piezoelectric bismuth ferrite (BiFeO(3)) films. Electric field-dependent studies show that a tetragonal-like phase can be reversibly converted into a rhombohedral-like phase, accompanied by measurable displacements of the surface, making this new lead-free system of interest for probe-based data storage and actuator applications.

• 出版日期2009-11-13