Un estudio de las propiedades estructurales, magnéticas y eléctricas de los compuestos Ba1-xNaxCoO3(x = 0.25, 0.5, 0.75)

Abstract

Cobaltite-like materials having metal-insulator transitions are relevant in the consumer electronics market. In this work, we present the structural, magnetic, and electrical properties of Ba1-xNaxCoO3 (with x= 0.25, 0.5, 0.75) cobaltite. All samples were synthesized using a solid-state reaction process. Their crystal structure was determined using X-ray diffraction (XRD) data by the Rietveld method, which showed that all the samples were crystallized in the orthorhombic space group C2221 (N.° 20). The microstructure of the sintered samples was characterized by scanning electron microscopy (SEM). The magnetic susceptibility measurements confirmed a paramagnetic behavior for x≥ 0.5 in the temperature range that was used. Likewise, a broad peak around 33 K in the sample x = 0.25, and characteristic of antiferromagnetic behaviors were observed. On the other hand, resistivity contributed to determining the insulating behavior of samples where x = 0.5 and x = 0.75. In contrast, at low sodium content (x = 0.25), a metal-insulator transition was observed with transition temperature near 105 K.