硅酸盐学报2012，Vol.40Issue(7)：1018-1022,5.
La8/9Sr1/45Na4/45MnO3/0.5x（V2O5）复合体系的电输运及磁电阻
Electric Transport and Magnetoresistance in La8/9Sr1/45Na4/45MnO3/0.5x（V2O5） Composites
摘要
Abstract
The samples of La8/9Sr1/45Na4/45MnO3/0.5x（V2O5） （x = 0, 0.04, 0.08, 0.012, 0.16, 0.20） were prepared by a solid-state reaction method. The temperature stability of magnetoresistance and electric transport property in the system were investigated via X-ray diffraction （XRD）, scanning electron microscopy, resistivity-temperature （p-T） and magnetoresistance-temperature （RM-T） measurements. The results show that for all the samples, there is a insulator-metal transition from high temperature range to low temperature range. The insulator-metal transition temperature （Tp） shifts to high temperature with increasing V2O5 content. Two peaks appear in the p-T curves of the samples （x≤0.08） with a low V2O5 content, and they vanish in the samples （x ≥0.12） with a high V2O5 content. The magnetoresistance （RM） of the samples increases with decreasing temprerature in the low temperature range, as a characteristic of low-field magnetoresistance effect. The intrinsic magnetoresistance in the high temperature range decreases with increasing V2O5 content. The magnetoresistance of the samples of x = 0.16 and 0.20 in the temperature range of 319-283 K at 0.8 T is 6.4% and 5.8%, respectively. The RM temperature stability may be due to the competition between the tunneling magnetoresistance caused by surface phase and the intrinsic magnetoresistance caused by bulk phase. The intrinsic magnetoresistance in bulk phase caused by double exchange dominants in the high temperature range, and the tunneling magnetoresistance caused by interface magnetic disorder dominants in the low temperature range. The RM does not change with temperature in the middle temperature range.关键词
电输运性质/磁电阻温度稳定性/复合体/钙钛矿锰氧化物Key words
electric transport property/temperature stability ofmagnetoresistance/composite/perovskite manganite分类
物理学引用本文复制引用
唐永刚,王桂英,严国清,宋启祥,张明玉,彭振生..La8/9Sr1/45Na4/45MnO3/0.5x（V2O5）复合体系的电输运及磁电阻[J].硅酸盐学报,2012,40(7):1018-1022,5.基金项目
国家自然科学基金 （）
安徽省教育厅自然科学研究重点项目 （）
宿州学院教授（博士）基金（2011jb01，2011jb02）及宿州学院科研平台开放课题 （）
