Crossover of persistent photoconductivity in a phase-separated La_0.325Pr_0.3Ca_0.375MnO₃thin film

Abstract

A crossover from positive to negative persistent photoconductivity (PPC) has been observed in the thermal hysteresis region of a La 0.325 Pr 0.3 Ca 0.375 MnO 3 thin film. In the cooling process, the resistance shows downward relaxation in darkness. Light illumination induces a resistance drop and positive PPC is observed. However, upon warming, the resistance exhibits upward relaxation without illumination. Moreover, the response of the film to light illumination shows distinct behavior. The resistance decreases to a lower value when the illumination is switched on and then shows upward relaxation during illumination. It recovers to a higher value when the illumination is stopped, which characterizes negative PPC. The PPC ratio is −30.2% at 125 K with a light intensity of 3.06 mW mm −2 . These results are discussed based on the phase competition and phase stability switch between ferromagnetic metal and charge/orbital-ordered insulator states. The results may be important for practical applications in photoelectric devices.

Evolution of photoinduced effects in phase-separated Sm0.5Sr0.5Mn1−yCryO3 thin films

“…When the light is switched off, the resistance recovers partly and a multilevel metastable state can be obtained with stable resistance values. In general, the FM state is comparably stable to the CO state due to the double exchange interaction with the local FM order34. The metastable state is stabilized by the competition between the FM and CO states.…”

Finite-time generalized function matrix projective lag synchronization of coupled dynamical networks with different dimensions via the double power function nonlinear feedback control method

“…The synchronization of coupled dynamical networks has been a focus in various fields of science and engineering, especially in the field of control. In the past decade, the control and synchronization of coupled dynamical networks has attracted much attention, and some relevant theoretical results have been established [3][4][5][6][7][8][9][10][11][12][13]. In real-world applications, however, it is often desired that synchronization of coupled dynamical networks should be achieved in finite time as quickly as possible, particularly in engineering fields.…”