  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.
