摘要
The transport properties and magnetoresistance of electron-doped manganate / insulator composites （Lao.sTeo.2MnO3）l-x/（ZrO2）x （x = 0, 0.3, and 0.5） are investigated. It is found that the metal-insulator transition temperature of this system shifts to a lower value as the ZrO2 content increases. The introduction of ZrO2 enhances both the domain scattering and electron relative scattering in the metal transport region. In the adiabatic small polaron hopping transport region, the thermal activation energy seems invariable regardless of the ZrO2 content. The applica- tion of a magnetic field promotes the charge transportation capabilities of the composites, and the magnetoresistance is enhanced with an increase of the ZrO2 content. This could be attributed to the more remarkable modification effect of magnetic field on ordering degree in the composites than in pure Lao.sTe0.2MnO3.
The transport properties and magnetoresistance of electron-doped manganate / insulator composites （Lao.sTeo.2MnO3）l-x/（ZrO2）x （x = 0, 0.3, and 0.5） are investigated. It is found that the metal-insulator transition temperature of this system shifts to a lower value as the ZrO2 content increases. The introduction of ZrO2 enhances both the domain scattering and electron relative scattering in the metal transport region. In the adiabatic small polaron hopping transport region, the thermal activation energy seems invariable regardless of the ZrO2 content. The applica- tion of a magnetic field promotes the charge transportation capabilities of the composites, and the magnetoresistance is enhanced with an increase of the ZrO2 content. This could be attributed to the more remarkable modification effect of magnetic field on ordering degree in the composites than in pure Lao.sTe0.2MnO3.
基金
Project supported by the National Natural Science Foundation of China (Grant No.61078057)
the Northwestern Polytechnical University Foundation for Fundamental Research,China (Grant Nos.JC201048 and JC201155)
