Magnetoresistance and electron-hole exchange interaction in (Co_(1-x)ln_x)_2O_(3-v) concentrated ferromagnetic semiconductors

摘要

Systematic studies of electrical transport properties of (Co_(1-x)In_x)_2O_(3-v) concentrated ferromagnetic semiconductors were performed. Quantitative analysis demonstrated that spin dependent variable range hopping dominated the low temperature transport behavior. Moreover, it was found that ferromagnetic or antiferromagnetic coupling of electron-hole pair generated during the variable range hopping process is responsible for the negative or positive magnetoresistance, respectively. Our results not only illustrate the connection between magnetoresistance and electron-hole exchange interaction but also provide a unique method to detect the exchange interaction of electron-hole pair.