Magnetoresistance and current-voltage characteristics in La2/3Sr1/3MnO3/ZnO composites

The low field magnetoresistance and the current-voltage characteristics in the granular (La2/3Sr1/3MnO3)(x)/(ZnO)(1-x) composites are reported. These composites have the percolation threshold about 0.3, at which the magnetoresistance has a maximum (15.2%, at 80 K). The composites investigated by the current-voltage characteristics exhibit the completely different transport properties with increasing the diluting ratio x. These are attributed to the intrinsic nature of the gain boundary of the ferromagnetic La2/3Sr1/3MnO3 clusters. (c) 2007 Elsevier B.V. All rights reserved.