Structural, Electrical, and Thermoelectric Properties of La and Sr Co-Doped CaMnO3 Compounds

摘要

Polycrystalline samples of CaMnO3 and Ca0.98-xSrxLa0.02MnO3(x = 0.00, 0.02, 0.04, 0.06) were prepared by citrate sol-gel route. X-ray diffraction technique was used to confirm the single phase of the samples. Morphology, Elemental compositions were carried out using scanning electron microscopy energy dispersive spectroscopy respectively. Raman spectroscopy measurements reveal that the structural distortion is mainly due to the rotation of MnO6 octahedral than Jahn Teller. Electrical resistivity measurements were carried out on sintered samples using the DC four-probe method and they disclose that La and Sr Co-doping can lower the resistivity. Thermoelectric properties were evaluated in the range of 303 K and 673 K, indicating that the majority of charge carriers are electrons. Among all the prepared co-doped La/Sr samples, Ca0.94Sr0.04La0.02MnO3 possess a higher power factor.