Colossal electroresistance of a Pr_(0.7)Ca_(0.3)MnO_3 thin film at room temperature

摘要

The electronic conduction through a Pr_(0.7)Ca_(0.3)MnO_3 thin film is investigated by measurements using dc and pulsed biases. Semiconducting Pr_(0.7)Ca_(0.3)MnO_3 films sandwiched by electrodes show both hysteretic and asymmetric behaviors in current-voltage characteristics. The observed conduction characteristics exhibit the space-charge-limited-current effect, and the hysteretic behavior can be ascribed to a carrier trapping and detrapping of the trap sites in the manganite. The hysteresis induces a colossal electroresistance (CER) of more than 5000% at room temperature. The CER ratio is independent of the duration time of pulses from an infinite (dc) down to 150 ns, indicating that the carrier filling of all the traps can be completed within a short time.