Document Type


Publication Date

September 2019

Publication Title

Physical Review Materials



Issue Number





Materials Science and Engineering


The impact of single-axis lattice expansion on the optical response of BiFeO3 films is examined. Low-energy He implantation is used to tailor morphotropic phases of BiFeO3 films and study changes in their optical spectra with continuously increasing lattice expansion. He ion implantation of epitaxial rhombohedral (R)- and tetragonal (T)-like BiFeO3 films induces uniaxial out-of-plane strain that, on R-like films, eventually leads to a complete R-T phase transition. This approach allows us to provide insights into the optical response of BiFeO3 films. Strain doping of T-like films leads to a significant redshift of the optical absorption spectra that is theoretically explained by a lowering of Fe 3dt2g states. R-like films, on the other hand, show a less-pronounced sensitivity to uniaxial strain and a blueshift of about 250 meV at the strain-induced R-T transition. The results demonstrate that strain doping allows a deeper examination of the optical properties of epitaxial phases that are otherwise impossible to access by standard epitaxy.


SJSU users: Use the following link to login and access the article via SJSU databases.This article was published in Physical Review Materials, volume 3, issue 9, 2019, and can also be found online here.©2019 American Physical Society