Strained BiFeO3 films: rhombohedral-orthorhombic and rhombohedral-tetragonal phase transitions. Part IV: ultraviolet Raman spectroscopy study
Abstract
Epitaxial BiFe O3 films grown by molecular-beam epitaxy on substrates inducing different lattice-mismatch strain (YAl O3 , SrLaAl O4 , PrSc O3) have been studied by variable- temperature ultraviolet Raman spectroscopy. Temperature evolution of Raman spectra from BiFe O3 films indicates the phase transitions from rhombohedral to tetragonal phase in compressively strained films on YAl O3 and SrLaAl O4 substrates. The films grown on PrScO3 substrates are subject to ~ 1.3 % tensile strain, and undergo the transition from rhombohedral to orthorhombic phase at about 550-600 K. The temperature dependence of Raman intensities of certain characteristic peaks indicates the possibility of coexisting rhombohedral and orthorhombic phases in the temperature range 400-550 K. Raman results are consistent with the phase diagram calculated using the phase field model.
Supported by NSF and Research Corporation for Science Advancement.- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2011
- Bibcode:
- 2011APS..MARP33011T