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...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.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 20473038.
文摘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.