La_(0.67-x)Sm_xSr_(0.33)MnO_3(x=0.40,0.50,0.60)体系的磁、电行为

The Magnetic,Electrical Behavior of La_(0.67-x)Sm_xSr_(0.33)MnO_3(x=0.40,0.50,0.60)System

测量了La0.67-xSmxSr0.33MnO3(x=0.40,0.50,0.60)体系的M-T曲线,ρ-T曲线和MR-T曲线。实验结果表明:x=0.40时,样品为长程铁磁有序;x=0.50时,样品为自旋团簇玻璃态;x=0.60时,样品在低温时表现为反铁磁状态。高掺杂(x=0.60)样品的输运行为发生异常,在Tc附近发生绝缘体-金属相变后,又发生金属-绝缘体相变的现象,这在ABO3结构中很少出现。体系的磁电行为变化取决于掺杂引起的额外磁性和晶格畸变效应。

The M-T curve and ESR curve and p-T curve of La0.67-xSmxSr0.33MnO3（x=0.40,0.50,0.60） were measured. The experimental result shows that the system displays long-range ferromagnetic order when x=0.40; the system displays spin cluster glass state when x=0.50; the system displays antiferromagnetic state at the low temperature when x=0.60. The transport behavior of the system appears exceptionally when highly doped, for x=0.60. It is found that there is a transition from metal to insulator after the occurrence of insulator-metal transition near To, which seldom occurs in AB03 structure. The magneto-electric behaviors of the system attributes to the extra magnetism and lattice distortion effect.