Topotactic Metal–Insulator Transition in Epitaxial SrFeOx Thin Films

• DOI: 10.1002/adma.201606566
• Publication Date: 2017-07-31T07:23:00Z
• Authors: Amit Khare; Dongwon Shin; Tae Sup Yoo; Minu Kim; Tae Dong Kang; Jaekwang Lee; Seulki Roh; In‐Ho Jung; Jungseek Hwang; Sung Wng Kim; Tae Won Noh; Hiromichi Ohta; Woo Seok Choi
• Keywords: Brownmillerite

Topotactic phase transformation enables structural transition without losing the crystalline symmetry of parental and provides an effective platform for elucidating redox reaction oxygen diffusion within metal oxides. In addition, it tuning emergent physical properties complex oxides, through strong interaction between lattice electronic degrees freedom. this communication, structure evolution SrFeOx epitaxial thin films is identified in real-time, during progress reversible topotactic transformation. Using real-time optical spectroscopy, two structurally distinct phases (i.e., brownmillerite perovskite) quantitatively monitored, a pressure-temperature diagram constructed first time. The at relatively low temperatures attributed to markedly small difference Gibbs free energy compared known similar class materials date. This study highlights stability reversibility films, which highly relevant environmental applications exploiting reactions.