摘要
We investigate the giant magnetoresistance of composites （La1-xAgzMnO3）1-υ（MnO2/Mn2O3）υ. The magnetoresistive property of the composites shows the characteristics of intergranular tunnelling. A conductivity leap has been observed around y = 0.7. The composite （La0.926Ag0.074MnO3）0.698（MnO2/Mn2O3）0.302 has been found to show the greatest magnetoresistance in the samples. Its room-temperature MR ratio reaches 24% under a field of 1.8T. These phenomena suggest a percolation transformation and a kind of field-induced fluctuation in percolation in the samples investigated.
We investigate the giant magnetoresistance of composites （La1-xAgzMnO3）1-υ（MnO2/Mn2O3）υ. The magnetoresistive property of the composites shows the characteristics of intergranular tunnelling. A conductivity leap has been observed around y = 0.7. The composite （La0.926Ag0.074MnO3）0.698（MnO2/Mn2O3）0.302 has been found to show the greatest magnetoresistance in the samples. Its room-temperature MR ratio reaches 24% under a field of 1.8T. These phenomena suggest a percolation transformation and a kind of field-induced fluctuation in percolation in the samples investigated.
基金
Supported by the National Natural Science Foundation of China under Grant No 20473038.
