Reversal transient laser-induced voltages in La_2/3Ca_1/3MnO₃ films

This paper reports that the transient laser-induced voltages have been observed in La_2/3Ca_1/3MnO₃ thin films on MgO (001) in the absence of an applied current. A peak voltage of \sim 0.15 V was detected in response to 0.015 J pulse of 308 nm laser. It is demonstrated that the signal polarity is reversed when the films are irradiated through the substrate rather than at the air/film interface. Off-diagonal thermoelectricity may support the inversion of the signal when the irradiation direction is reversed.