Erasure of photoconductivity by magnetic field in oxygen-deficient La2/3Sr1/3MnO3-δ thin films

Both transient and persistent photoconductivities (abbreviated to TPC and PPC, respectively) are observed in oxygen-deficient La2/3Sr1/ 3MnO3-delta thin films at low temperatures. The magnitudes of TPC and PPC are 7.6% and 6.08%, respectively, with light density of 4.35 mW/cm(2) at 50 K. Moreover, a small magnetic field can erase most of PPC effect sharply. The proportion of PPC erased by magnetic field achieves 73% in magnetic field of 0.001 T and 97.5% in 0.5 T. Electrons trapped by oxygen vacancies are released by the magnetic field and recombine with holes are suggested to be the origin for depression of PPC effect. (c) 2006 American Institute of Physics.