Effect of cobalt on the magnetoresistance characteristics of rare-earth doped manganites  

作　　者：江阔 宫声凯 

机构地区：[1]Department of Defence Science and Technology,Southwest University of Science and Technology [2]Department of Materials Science and Engineering,Beijing University of Aeronautics and Astronautics

出　　处：《Chinese Physics B》2009年第7期3035-3039,共5页中国物理B（英文版）

基　　金：Project suppprted by the doctor start-up fund of the Southwest University of Science and Technology of China (Grant No07ZX0110)

摘　　要：The effect of cobalt-doping on the magnetic,transport and magnetoresistance characteristics of La1-xSrxMnO3 was investigated.The results show that the magnetoelectric property of rare-earth doped manganites is greatly affected by substitution of Co for Mn sites.The Curie temperature as well as the magnetic moment decreases with the increase of doping concentration,and the samples exhibit obvious characteristics of the spin glass state.Moreover,the magnetoresistance is evidently modulated by doping concentration,and the relevant temperature dependence is also suppressed.In addition,low-temperature magnetoresistance is significantly promoted as doping concentration increases,which renders a value of approximately 50% in the temperature range of 5-200 K and varies within 12.5%.It can be attributed to the effect of spin scattering, induced by cobalt doping,on the itinerant electrons of Mn ions,thus introducing a spin-disorder region into the ferromagnetic region of double-exchange interaction between neighbouring Mn^3＋ and Mn^4＋ ions.The effect of cobalt-doping on the magnetic,transport and magnetoresistance characteristics of La1-xSrxMnO3 was investigated.The results show that the magnetoelectric property of rare-earth doped manganites is greatly affected by substitution of Co for Mn sites.The Curie temperature as well as the magnetic moment decreases with the increase of doping concentration,and the samples exhibit obvious characteristics of the spin glass state.Moreover,the magnetoresistance is evidently modulated by doping concentration,and the relevant temperature dependence is also suppressed.In addition,low-temperature magnetoresistance is significantly promoted as doping concentration increases,which renders a value of approximately 50% in the temperature range of 5-200 K and varies within 12.5%.It can be attributed to the effect of spin scattering, induced by cobalt doping,on the itinerant electrons of Mn ions,thus introducing a spin-disorder region into the ferromagnetic region of double-exchange interaction between neighbouring Mn^3＋ and Mn^4＋ ions.

关 键 词：cobalt-doped La1-xSrxMnO3 spin scattering magnetoresistance enhancement 

分 类 号：O482.5[理学—固体物理] TB332[理学—物理]