Ferromagnetism at room temperature in La0.8Ca0.2MnO3 thin films

Anomalously high metal–insulator transition temperature $T_p$ and ferromagnetic transition temperature $T_c$ have been observed in thin films of ${\mathrm{La}}_{\mathrm{0.8}}{\mathrm{Ca}}_{\mathrm{0.2}}{\mathrm{MnO}}_{\mathrm{3}}.$ Ferromagnetic resonance signals from microwave studies are observed at room temperature (well above $T_c)$ suggesting the presence of multiple magnetic spin systems. The $T_p$ and $T_c$ values are higher than that of ${\mathrm{La}}_{\mathrm{0.67}}{\mathrm{Ca}}_{\mathrm{0.33}}{\mathrm{MnO}}_{\mathrm{3}}$ which have the highest $T_p$ and $T_c$ according to the bulk phase diagram. These results suggest that properties well beyond those seen in the bulk phase diagram may be achievable in thin films of the manganites.