Strain-induced crossover of the metal-insulator transition in perovskite manganites

Abstract

The essential role of strain in determining the electronic states of perovskite manganites is clearly demonstrated in the form of anisotropic and substrate-dependent crossover of a first-order phase transition in charge-orbital ordered epitaxial thin films of ${({\mathrm{Nd}}_{1\ensuremath{-}x}{\mathrm{Pr}}_{x})}_{0.5}{\mathrm{Sr}}_{0.5}{\mathrm{MnO}}_{3}$. An application of (110)-oriented epitaxial growth technique allows the structural flexibility indispensable for the large anisotropic lattice deformation at the first-order transition. The technique enables us to fine-tune the Jahn-Teller distortion for manipulating the metal-insulator transition in thin films, a first step toward the strongly correlated electron devices.