Thickness dependence of the stability of the charge-ordered state inPr0.5Ca0.5MnO3thin films

Thin films of the charge-ordered (CO) compound ${\mathrm{Pr}}_{0.5}{\mathrm{Ca}}_{0.5}{\mathrm{MnO}}_3$ have been deposited onto (100)-oriented ${\mathrm{SrTiO}}_3$ substrates using pulsed laser deposition. Magnetization and transport properties are measured when the thickness of the film is varied. While the thinner films do not exhibit any temperature-induced insulator-metal transition under an applied magnetic field up to 9 T, for thickness larger than 1100 Å a 5 T magnetic field is sufficient to melt the CO state. We have established the temperature-field phase diagram and compared it to the bulk material. It indicates that the robustness of the CO state in thin films depends strongly on the strains and the thickness. We proposed an explanation based on the distortion of the cell of the film.