La_(0.6)Sr_(0.15)Na_(0.1)□_(0.15)MnO_3+xAgNO_3复合体系的结构、磁性及磁电阻的温度稳定性研究

Study on Structure , Magnetic Properties and Temperature Stability of La_(0.6)Sr_(0.15)Na_(0.1)□_(0.15)MnO_3+xAgNO_3

采用固相反应法制备了La0.6Sr0.15Na0.1□0.15MnO3+xAgNO3(x=0.08、0.16、1.00,x为物质的量比,□代表空位)系列复合材料样品,对复合样品的相结构、磁性质及其磁电阻效应进行了研究。通过相结构的研究发现:复合样品近似呈现La0.6Sr0.15Na0.1□0.15MnO3/Ag/Mn3O4的特殊复合结构。通过对磁电阻的研究发现:复合样品不同程度地提高了母体样品的MR峰值,降低了峰值温度,使其更接近室温。在204～280K的温度范围内和1.8T外磁场作用下,当x=0.08时,MR保持在(4.70±0.25)%;x=0.16时,MR保持在(7.20±0.28)%。所以,复合样品较之母体样品,磁电阻的温度稳定性有了很大提高。

A series of composite samples of La0.6Sr0.15Na0.1□0.15MnO3＋xAgNO3（x=0. 08,0. 16,1.00,x is mol ratio, □ is vacancy） were prepared by solid state reaction. It is found that the compound samples show structures similar to La0.6Sr0.15Na0.1□0.15MnO3＋xAgNO3 composite. Magnetoresistance （MR） measurement demonstrates increase in peak MR and decrease in the corresponding temperatures in all the composite samples with respect to their matrix samples. In the temperature range of 204-280 K and under 1.8 T external magnetic field, MR maintains at （4. 70±0. 25）% when x=0. 08, and （7. 20±0. 28）% when x=0. 16. Therefore, in the composite samples, temperature stability of magnetoresistance has greatly improved over the matrix samples.