Growth rate induced monoclinic to tetragonal phase transition in epitaxial BiFeO3 (001) thin films

Abstract

Epitaxial BiFeO3 thin films were deposited on SrRuO3 buffered SrTiO3 (001) substrates at different growth rates by varying the radio frequency sputtering power. With increasing growth rate, the crystal structure of BiFeO3 films develops from monoclinic lattice to a mixture phase of tetragonal lattice T1 with c/a∼1.05 and giant tetragonal lattice T2 with c/a∼1.23, finally to a single tetragonal phase T2, as shown by high resolution synchrotron x-ray diffraction reciprocal space mappings. The observed phase transitions, induced by film growth rate, offer an alternative strategy to manipulate crystalline phases in epitaxial ferroelectric thin films. © 2011 American Institute of Physics.