Thermal Hysteresis in La_2/3 Ca_1/3 MnO₃ Films Grown on Tilted SrTiO₃ Substrates and Influence of External Magnetic Field

Thermal hysteresis in the resistivity of La_2/3Ca_1/3MnO₃ thin films grown on tilted SrTiO₃ substrates is simulated by using the random network model on the basis of mixed-phase percolation between metallic and insulating domains. The metallic-insulating transition temperatures during the warming process are lower than those during the cooling process due to the difference in fraction of metallic domains between warming and cooling process. With an external magnetic field, the metallic--insulating transition temperatures shift to a higher value and the resistivities are reduced. The excellent agreement between the simulation and the experimental data further verifies that phase separation plays a crucial role in the transport process of La_2/3Ca_1/3MnO₃ thin films.