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arXiv · 1003.2828

Polarized Raman spectroscopy of nearly-tetragonal BiFeO$_3$ thin films

M. N. Iliev·M. V. Abrashev·D. Mazumdar·V. Shelke·A. Gupta
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Abstract

BiFeO$_3$ thin films can be epitaxially stabilized in a nearly-tetragonal phase under a high biaxial compressive strain. Here we investigate the polarized Raman spectra of constrained BiFeO$_3$ films with tetragonal-like (BFO-T), rhombohedral-like (BFO-R) and multiphase (BFO-T+R) structure. Based on analysis of the number and symmetry of the Raman lines, we provide strong experimental evidence that the nearly-tetragonal films are monoclinic ($Cc$ symmetry) and not tetragonal $(P4mm)$. Through the Raman mapping technique we show localized coexistence of BFO-T and BFO-R phases with the relative fraction dependent on the film thickness.

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M. N. Iliev, M. V. Abrashev, D. Mazumdar, V. Shelke, A. Gupta. 2010-03-14. Polarized Raman spectroscopy of nearly-tetragonal BiFeO$_3$ thin films. https://doi.org/10.1103/physrevb.82.014107

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