%0 Journal Article
%T Simultaneous observation of positive and negative giant magnetoresistances in composite (La0.83Sr0.17MnO3)1－x(ITO)x
%A 王淼
%A 张宁
%J 中国物理 B
%D 2006
%I 
%X We have studied the transport property of the composites （La0.83Sr0.17 MnO3）1-x（ITO）x ITO=（In2O3）0.95 （SNO2）0.05], which were fabricated by mechanically mixing La0.83Sr0.17MnO3 and ITO grains. A giant positive magnetoresistance （PMR） has been observed above the Curie temperature Tc for samples with x around 0.40, in addition to the negative magnetoresistanee related to spin-dependent interracial tunnelling below To. For （La0.83Sr0.17MnO3）0.6（ITO）0.4, the magnetoresistive ratio for the PMR can reach 39.3% under a magnetic field H=2.24×10^5A/m. Theoretical analysis suggests that the magnetic-field-induced broadening of the p-n barrier between both kinds of grains and the density of the p-n heterostructures should be responsible for the PMR behaviour.
%K 粒状系统
%K 磁致电阻
%K p-n异质结构
%K 输运特性
%K 半导体物理
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=6E709DC38FA1D09A4B578DD0906875B5B44D4D294832BB8E&cid=47EA7CFDDEBB28E0&jid=CD8D6A6897B9334F09D8D1648C376FB4&aid=5010C6F0B122A1B92AB5114184A59812&yid=37904DC365DD7266&vid=23CCDDCD68FFCC2F&iid=E158A972A605785F&sid=138D3449C4A7D4E9&eid=970314C3B74F6C4D&journal_id=1009-1963&journal_name=中国物理&referenced_num=0&reference_num=23