Co_x-C_(1-x)复合块材的微结构和巨磁电阻效应

Microstructures and Giant Magnetoresistance Effect of Co_x- C_(1- x ) Bulk Composites

采用热压法制备了一系列不同Co含量x的CoxˉC1 x(质量分数)复合块材样品,并对样品的巨磁电阻效应进行了研究。光谱分析发现颗粒尺寸在50～200μm,室温下,磁场强度为1.03×106A/m时,在Co10C90样品中测出的最大磁电阻值为20%。随着磁场强度增加,磁电阻值还会增大。并且发现当x=10,30,60时,磁电阻存在三个峰值分别为20%,17.5%,9%。

A series of (Co_ x )ˉ (C_(1- x )) bulk composites was fabricated by hot-pressing method. The giant magnetoresistance(GMR)effect of samples was investigated. The structures and sizes of grains in the samples were investigated using an optical microscope. The size of the scattered grains roughly distributed between 50 and 200 μm was found.The GMR value of the Co_(10)C_(90)bulk composites was as large as 20% under an applied magnetic field of 1.03×10~6A/m at room temperature. For a high enough field, the GMR ratio would be much larger than 20%.Three peak maximums of Co content curves were 20%,17.5%,9%,when Co content was 10%,30%,60% respectively.