Breakdown of the charge-ordered state inNd0.5Sr0.5MnO3

It was found that photocurrent or electric-field induced current passing through a ${\mathrm{Nd}}_{0.5}{\mathrm{Sr}}_{0.5}{\mathrm{MnO}}_3$ sample in the charge-ordered state could cause a nontransient drop in resistance. It is proposed that a breakdown of the charge-ordered state was induced by current and that metallic filaments are created. This effect largely differs from the electric breakdown or photoinduced transition previously observed in ${\mathrm{Pr}}_{1-x}{\mathrm{Ca}}_x{\mathrm{MnO}}_3,$ $0.3<~x<~0.5;$ because no voltage was necessary to sustain the lower resistance state. The effect was reproducible and reversible by annealing the sample at room temperature.