Electric transport properties and temperature stability of magnetoresistance of composite system between La_(8/9)Sr_(1/45)Na_(4/45)MnO_3 and Sb_2O_3  

作　　者：Gui-Ying Wang Yong-Gang Tang Qi-Xiang Song Ming-Yu Zhang Zhen-Sheng Peng 

机构地区：[1]Anhui Key Laboratory of Spintronic and Nano-materials Research [2]School of Mechanical and Electronic Engineering,Suzhou University

出　　处：《Rare Metals》2013年第4期363-368,共6页稀有金属（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.19934003);the Natural Science Foundation of the Education Bureau of Anhui Province,China(Nos.KJ2011A259 and KJ2012Z404);Anhui Key Laboratory of Spintronics and Nano-materials Program(Nos.2010YKF01 and 2010YKF04);the Professors’and Doctors’ Research Startup Foundation of Suzhou University(Nos.2011jb01 and 2010jb02)

摘　　要：The samples ofLa8/9Sr1/45Na4/45MnO3 （LSNMO）/x/2（Sb2O3） were prepared by the solid-state reaction method. The electric transport properties and the temperature stabil-ity of magnetoresistance （MR） of the samples were studied through the measurements of X-ray diffraction patterns, resistivity-temperature （ρ-T） curves, mass magnetization-temperature （σ-T） curves, and magnetoresistance-temper-ature （MR-T） curves. The results indicate that the p-Tcurves of the original material LSNMO show two peaks, and the phenomenon of two peaks of ρ-T curves disappears for the composite samples, which can be explained by a competition between surface-phase resistivity induced by boundary-dependent scattering and body-phase resistivity induced by paramagnetism-ferromagnetism transition. For all the sam-ples in the low temperature range, MR increases continu-ously with the decrease of temperature, which shows a characteristic of low-field magnetoresistance. However, MR basically keeps the same in the high temperature range. The paramagnetism-ferromagnetism transition is observed in the high temperature range due to a composite between perov-skite manganite and insulator, which can enhance the tem-perature of MR appearance in the high temperature range and make it to appear near room temperature. For the sample with x = 0.12, MR remains constant at the value of 7.5 % in the temperature range of 300-260 K, which achieves a tem-perature stability of MR near room temperature. In addition,for the sample with x = 0.16, MR is above 6.8 % in the high temperature range of 318-252 K （△T = 66 K）. MR almost remains constant in this temperature range, which favors the practical application of MR.The samples ofLa8/9Sr1/45Na4/45MnO3 （LSNMO）/x/2（Sb2O3） were prepared by the solid-state reaction method. The electric transport properties and the temperature stabil-ity of magnetoresistance （MR） of the samples were studied through the measurements of X-ray diffraction patterns, resistivity-temperature （ρ-T） curves, mass magnetization-temperature （σ-T） curves, and magnetoresistance-temper-ature （MR-T） curves. The results indicate that the p-Tcurves of the original material LSNMO show two peaks, and the phenomenon of two peaks of ρ-T curves disappears for the composite samples, which can be explained by a competition between surface-phase resistivity induced by boundary-dependent scattering and body-phase resistivity induced by paramagnetism-ferromagnetism transition. For all the sam-ples in the low temperature range, MR increases continu-ously with the decrease of temperature, which shows a characteristic of low-field magnetoresistance. However, MR basically keeps the same in the high temperature range. The paramagnetism-ferromagnetism transition is observed in the high temperature range due to a composite between perov-skite manganite and insulator, which can enhance the tem-perature of MR appearance in the high temperature range and make it to appear near room temperature. For the sample with x = 0.12, MR remains constant at the value of 7.5 % in the temperature range of 300-260 K, which achieves a tem-perature stability of MR near room temperature. In addition,for the sample with x = 0.16, MR is above 6.8 % in the high temperature range of 318-252 K （△T = 66 K）. MR almost remains constant in this temperature range, which favors the practical application of MR.

关 键 词：Electric transport property Temperaturestability of magnetoresistance Two-phase composite Perovskite manganite 

分 类 号：O441.6[理学—电磁学]