TY - JOUR
T1 - An empirical approach to measuring interface energies in mixed-phase bismuth ferrite
AU - Burns, Stuart R.
AU - Paull, Oliver
AU - Bulanadi, Ralph
AU - Lau, Christie
AU - Sando, Daniel
AU - Gregg, J. Marty
AU - Valanoor, Nagarajan
PY - 2021/3/9
Y1 - 2021/3/9
N2 - 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 ± 21 and 426 ± 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.
AB - 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 ± 21 and 426 ± 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.
U2 - 10.1103/PhysRevMaterials.5.034404
DO - 10.1103/PhysRevMaterials.5.034404
M3 - Article
VL - 5
JO - Physical Review Materials
JF - Physical Review Materials
SN - 2475-9953
IS - 3
M1 - 034404
ER -