The essentials for the control of charge-orbital ordering in thin films of perovskite manganites

Gigantic responses arising from the melting of charge-orbital ordering (COO) in perovskite manganites have been attractive both in material science and technologies. We review the essentials to realize such phenomena in a thin film form aiming at a possible application to correlated electron devices, namely, the role of epitaxial strain on (1 1 0) substrates. The crucial issues in designing the correlated electron interfaces of (0 0 1), (1 1 0), and (2 1 0) are also discussed. In addition, the epitaxial growth of high-Tco materials such as (Bi, Sr)MnO3 and A-site ordered SmBaMn2O6 thin films is described, which is indispensable towards room temperature operation of correlated electron devices.