Positive colossal magnetoresistance effect in ZnO∕La0.7Sr0.3MnO3 heterostructure

In this letter, an oxide heterostructure has been fabricated by successively growing La0.7Sr0.3MnO3 and ZnO layers on a LaAlO3 (100) substrate using pulsed laser deposition. The ZnO∕La0.7Sr0.3MnO3 heterostructure exhibits good rectifying behavior and a positive colossal magnetoresistance (MR) effect over a temperature range of 77–280K. The maximum MR values are determined to be about 53.9% at H=0.5T and 36.4% at H=0.3T. A possible explanation is given in terms of the effect of magnetic fields on the depletion layer and the capture carriers effect at the interface.