1. An empirical approach to measuring interface energies in mixed-phase bismuth ferrite
- Author
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Burns, Stuart R., Paull, Oliver, Bulanadi, Ralph, Lau, Christie, Sando, Daniel, Gregg, J. Marty, and Valanoor, Nagarajan
- Subjects
Condensed Matter - Materials Science - Abstract
In complex oxide heteroepitaxy, strain engineering is a powerful tool to obtain phases in thin films that may be otherwise unstable in bulk. A successful example of this approach is mixed phase bismuth ferrite (BiFeO3) epitaxial thin films. The coexistence of a tetragonal-like (T-like) matrix and rhombohedral-like (R-like) striations provides an enhanced electromechanical response, along with other attractive functional behaviors. In this paper, we compare the energetics associated with two thickness dependent strain relaxation mechanisms in this system: domain walls arising from monoclinic distortion in the T-like phase, and the interphase boundary between the host T-like matrix and tilted R-like phases. Combining x-ray diffraction measurements with scanning probe microscopy, we extract quantitative values using an empirical energy balance approach. The domain wall and phase boundary energies are found to be 113 $\pm$ 21 and 426 $\pm$ 23 mJ.m$^{-2}$, respectively. These numerical estimates will help us realize designer phase boundaries in multiferroics, which possess colossal responses to external stimuli, attractive for a diverse range of functional applications., Comment: 21 pages, 5 figures. Submitted to Phys. Rev. Mater
- Published
- 2021
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