Epitaxial-strain effect on charge/orbital order in Pr0.5Ca0.5MnO3 films

TL;DR

This study investigates how epitaxial strain from different substrate orientations influences charge and orbital ordering in Pr0.5Ca0.5MnO3 thin films, revealing that growth orientation significantly affects transition temperatures and domain sizes.

Contribution

It demonstrates that epitaxial strain from substrate orientation can control charge and orbital order properties in Pr0.5Ca0.5MnO3 films, a novel insight into strain engineering.

Findings

(011)-film has a CO-OO transition around 220 K, similar to bulk.

(001)-film shows a higher transition temperature around 300 K.

Domain size of orbital order is three times larger in (011)-film.

Abstract

Effect of growth orientation on charge- and orbital-ordering (CO-OO) phenomena has been studied for Pr0.5Ca0.5MnO3 epitaxial thin films fabricated on (LaAlO3)0.3-(SrAl0.5Ta0.5O3)0.7 (LSAT) substrates by means of resistivity, synchrotron x-ray diffraction, and polarized optical microscopy measurements. CO-OO transition is observed around 220 K for a film grown on an LSAT (011) substrate ((011)-film), similarly to a bulk sample, while a film grown on a (001) plane of LSAT ((001)-film) shows much higher transition temperature around 300 K. The domain size of OO is approximately 3 times as large in the (011)-film as in the (001)-film. These results demonstrate that various properties of CO-OO phenomena can be controlled with the growth orientation via the epitaxial strain from the substrate.