掺杂钙钛矿钴氧化物的制备、表征及其电磁性质

掺杂钙钛矿钴氧化物的制备、表征及其电磁性质

[摘要]：采用溶胶-凝胶的方法制备了La0.75Sr0.25Co1-xFexO3 (x=0,0.

1)多晶样品,对样品凝胶进行热分析, 了解样品在不同温度下发生的物理、化学变化，通过室温X射线衍射检测样品的单相性, 用NT-MDT型原子力显微镜对样品的微观形貌及颗粒度进行表征； 用振动样品磁强计以及标准4探针法对样品进行了电磁性能的研究．结果表明铁的掺入晶格结构基本没有发生变化，但掺铁后体系电阻率增大，出现半导体－金属的转变，由于Fe的掺入，1方面，铁离子替代钴离子减小了Co3+/Co4+ 的比例，从而削弱了原有的Co-O-Co之间的双交换作用形成的铁磁有序，另1方面增强了由Co-O-Fe以及Fe-O-Fe之间的超交换作用形成的反铁磁有序.而且发现材料磁性明显下降，转变温度向低温方向移动，系统在低温下由自旋团簇玻璃态转变为自旋玻璃态．

[关键词]：2级相变，掺杂钙钛矿钴氧化物，铁磁有序，反铁磁有序，自旋玻璃态

The study of synthesis ,characterization and magnetic and electric properties of doping perovskite cobalt oxide compound

[Abstract]: Used the sol - gelatin the method to prepare the La0.75Sr0.25Co1-xFexO3 (x=0,0.

1) polytropism sample, carried on the thermal analysis to the sample gelatin, understood sample physics, chemical change which occurred under the different temperature, through room temperature X beam diffraction examination sample single-phase, carried on the attribute with the NT-MDT atomic force microscope to the sample microscopic appearance and the granularity; Moreover analyzes the material with the infrared spectroscope chemistry band structure; Have conducted the electromagnetism performance research with the vibration sample magnetometer as well as the standard four probe method to the sample. The result indicated the iron mixes in the lattice structure basically not to change, after but mixes the iron the system electronic resistivity to increase, appears the semiconductor - metal the transformation, because Fe blend, on the one hand, the hard ion substitution cobalt ion reduced the Co3+/Co4+ proportion, thus weakened the ferromagnetic order which between the original Co-O-Co double substitution forms, on the other hand strengthened over-delivers by between Co-O-Fe as well as Fe-O-Fe trades the counter-ferromagnetic order which the function forms. Moreover discovery material magnetism drops obviously, the transition temperature to the low temperature traverse, the system for spins the glass under the low temperature by the spinning group bunch of glass condition transformation condition.

[Keyword]: two-level phase change, the doping perovskite cobalt oxide compound, ferromagnetic order; anti-ferromagnetic order; spin-glass phase.

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