A位的Gd掺杂对La_(0.7)Sr_(0.3)MnO_3体系磁电性质的影响

The influence of Gd doping at A site on the magnetic and electrical properties in La_(0.7)Sr_(0.3)MnO_3

通过实验研究了La0 7-xGdxSr0 3MnO3(x =0 0 0 ,0 10 ,0 15 ,0 2 0 ,0 30 ,0 4 0 ,0 5 0 ,0 6 0 ,0 70 )体系的M T曲线、M H曲线、红外光谱、拉曼光谱、ρ T曲线和MR T曲线 .实验结果表明 :随着Gd掺杂的增加 ,体系从长程铁磁有序向自旋团簇玻璃态和反铁磁状态转变 ,高掺杂时的输运性质在其磁背景下发生异常 .Gd掺杂引起的磁结构变化和额外的磁性耦合将导致庞磁电阻效应 .

The M-T curves, M-H curves, infrared spectra, Raman spectra,ρ-T curves and MR-T curves of La 0.7-xGd xSr 0.3MnO 3 (x=0.00, 0.10, 0.15, 0.20, 0.30, 0.40, 0.50, 0.60, and 0.70) are st udied. The experimental results indicate that with increasing Gd doping, the sys tem undergoes a transition from long-range ferromagnetic order to the cluster- spin glass state and further to an antiferromagnetic order. With heavily doping content, the transport property exhibits an abnormal behavior under magnetic bac kground. The variation in magnetic structure and extra magnetic coupling caused by Gd doping lead to colossal magnetoresistance.