Epitaxial strain effect in perovskite RENiO3 films (RE = La–Eu) prepared by metal organic decomposition

Abstract

We report the synthesis of perovskite RENiO3 films (RE=La, Pr, Nd, Sm, and Eu) by metal organic decomposition (MOD). The RENiO3 family is an ideal system for studying the metal–insulator transition due to the simplicity of the materials. One of the drawbacks is that the bulk synthesis of the RENiO3 requires processing at high oxygen pressures to stabilize Ni3+. Fundamentally, MOD is similar to solid-state reaction, but it turned out that the MOD synthesis tends to stabilize RENiO3 without the need for high oxygen pressure. The films prepared by MOD show high crystallinity and low resistivity. Furthermore, we have investigated the epitaxial strain effect and observed a dramatic effect in PrNiO3 and NdNiO3 films on LaAlO3 substrates. The metal–insulator transition in the PrNiO3 films on LaAlO3 is fully suppressed, whereas the metal–insulator transition temperature is considerably lowered in the NdNiO3 films on LaAlO3.