Structural, Electrical, and Thermoelectric Properties of La and Sr Co-Doped CaMnO 3 Compounds

Abstract

Polycrystalline samples of CaMnO 3 and Ca 0.98-x Sr x La 0.02 MnO 3 (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 MnO 6 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, Ca 0.94 Sr 0.04 La 0.02 MnO 3 possess a higher power factor.