Strain-stabilized charge ordering and magnetorelaxor behaviors in Cr-doped Pr_0.5Ca_0.5MnO₃ epitaxial thin films

Thin films of a magnetorelaxor compound, Pr_0.5Ca_0.5Mn_1-yCr_yO₃ were grown on various substrates. Strain-free and polycrystalline thin films on MgO substrates well reproduce the properties reported for the bulk samples. Pseudomorphically strained and atomically smooth epitaxial thin films grown on perovskite substrates show strain-driven modification of the properties. Being consistent with the orbital ordering accompanied with charge ordering, tensile strain anomalously stabilizes the charge-ordered (CO) state. Compressive strain also suppresses ferromagnetism but high-Cr doping (y=0.10) induces magnetorelaxor behaviors, where the volume ratio of coexisting CO and ferromagnetic phases can be tuned and memorized by the history of the magnetic-field application. © 2001 American Institute of Physics.