Magnetoresistive properties of Ni-doped La_(0.7)Sr_(0.3)MnO_3 manganites  

作　　者：Ahmed Mohamed Ahmed Abd El-Moez Ahmed Mohamed Medhat Abdelrady Abdellateef Hassan Ahmed Abd El-Ghanny 

机构地区：[1]Physics Department,Faculty of Science,Sohag University

出　　处：《Rare Metals》2016年第7期551-558,共8页稀有金属（英文版）

基　　金：financially supported by Sohag University in Egypt

摘　　要：Lao.7Sr0.3Mnl_xNixO3 （x = 0, 0.025, 0.050 and 0.075） ceramics were prepared by the conventional solid-state reaction method. The partial substitution of Mn by Ni2＋ leads to a decrease in cell volume as well as a structural transition from the rhombohedral to the orthorhombic structure. Ni2＋ doping increases the electrical resistivity, decreases the semiconductor-metal transition temperature （Tms） and relatively enhances the room temperature magnetoresistance （MR）, especially in x = 0.025 and around Tins. With respect to conduction mechanism, the small polaron hopping （SPH） and the variable range hopping （VRH） models were used to ex- amine conduction in the semiconducting region.Lao.7Sr0.3Mnl_xNixO3 （x = 0, 0.025, 0.050 and 0.075） ceramics were prepared by the conventional solid-state reaction method. The partial substitution of Mn by Ni2＋ leads to a decrease in cell volume as well as a structural transition from the rhombohedral to the orthorhombic structure. Ni2＋ doping increases the electrical resistivity, decreases the semiconductor-metal transition temperature （Tms） and relatively enhances the room temperature magnetoresistance （MR）, especially in x = 0.025 and around Tins. With respect to conduction mechanism, the small polaron hopping （SPH） and the variable range hopping （VRH） models were used to ex- amine conduction in the semiconducting region.

关 键 词：MANGANITES X-ray diffraction Structure Electrical resistivity MAGNETORESISTANCE 

分 类 号：TQ174.1[化学工程—陶瓷工业]