Synthesis and characterization of Li-doped LaMnO₃ CMR materials

Abstract

A series of bulk polycrystalline La_1−xLi_xMnO₃ samples with x ranging from 0.1 to 0.5 was prepared by sol-gel method. X-ray diffraction patterns show that the crystal structures are single rhombohedral perovskite for the x≤0.3 sample and the impurity appears when x>0.3. Under the same synthesized conditions, the higher Li content samples display a higher content of liquid phase content and larger mean grain sizes, which leads to the increases of the effect of the grain boundaries. The experimental results show that the change of the ferromagnetic transition temperature and the resistivity can attribute to the effect of the grain boundary and the connectivity of the inter grains as well as the ratio of Mn³⁺ to Mn⁴⁺.

Keywords

sol-gel method / doped content / grain boundary / magnetotransport

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