Comparison of topotactic and magnetic structures for manganite oxide films

Deliberate manipulation of topotactic transformation via oxygen insertion/extraction offers a feasible way to precisely tune oxygen concentration, B-O coordination occupation and resultant electronic functionalities of perovskite (ABO(3))-based oxides. Herein, two methods, a post-annealing CaH2 treatment and an in-situ oxygen-vacancy diffusion using oxygen getter layer, were conducted to achieve topotactic transitions from perovskite to brownmillerite of La0.7Sr0.3MnO3-delta (LSMO, 0 <= delta <= 0.5) films. The results revealed that delicate control of oxygen composition is the crucial factor for evolutions of crystalline structure and subsequent magnetic properties of LSMO films. In particular, the brownmillerite LSMO film treated by the in-situ oxygen getter layer possesses desirable structural stability over time. In contrast, the topotactic LSMO films using reduction agents CaH2 exhibit compositional and structural inhomogeneities. These findings suggest that adjustable topotactic trans-formation through anionic oxygen provides a facile strategy for designing multifunctional perovskite-derivative oxide materials.

Automated summary

Deliberate manipulation of topotactic transformation through oxygen insertion and extraction is an effective method for controlling the crystalline structure and magnetic properties of perovskite-based oxides. The results of this study show that precise control of oxygen composition allows for adjustable topotactic transformation and using an in-situ oxygen getter layer leads to more stable structures.