Magnetoresistance and electroresistance of highly resistive states in thin nonhomogeneous La_(0.67)Ca_(0.33)MnO_3 films

摘要

The magnetoresistive and electroresistive properties of thin nonhomogeneous La_(0.67)Ca_(0.33)MnO_3 films have been investigated after thermocycling from 200 to 80 K. Highly resistive states with an additional low temperature resistance peak near 95 K were revealed in the films using probe currents as low as 1 μA. The film resistance at the peak is sensitive to the probe current strength and the applied magnetic field. The highly resistive state is metastable and is associated with the formation of martensitic inclusions during the thermocycling. The exhibition of memory effects during the cooling also suggests the idea of the presence of martensitic-type transformations.