Synthesis, structural, magnetic and electrical properties of La_(1-x)Cd_xMnO_3 manganites (0.1 = x = 0.5)

摘要

Cd-substituted LaMnO_3 compounds have been prepared using sol-gel method at a relatively low temperature of 900 deg C. The crystal structure examined by X-ray powder diffraction indicates that the samples were single phase and crystallize in a rhombohedral (R3-bar c) structure with increase the Cd content. The Rietveld refinement of the structure shows that the substitution of La by Cd in the La site changes the structure parameters, such as Mn-O bond length and Mn-O-Mn angles. Magnetic measurements reveal that the magnetization of these compounds exhibit a ferromagnetic to paramagnetic transition with an increasing in the Curie temperature T_C when x increases from 0.1 to 0.5. The resistivity measurements reveal that the samples exhibit a metallic to semiconductor transition and the electrical temperature transition T_P present a similar trend of T_C, with increasing the Cd content.