Influence of V5+ incorporation on the resistive and sintering properties of LaCo0.4Ni0.6O3 ceramic

Abstract

A series of LaCo0.4Ni0.6-xVxO3 (LCNV, x = 0.02–0.08) ceramics were synthesized via the solid-state reaction method, and their resistive and sintering properties were studied. X-ray diffraction and Rietveld refinement analysis were performed to identify the crystal structure of LCNV, and a slight increase in the lattice parameters was observed. Scanning electron microscopy and thermomechanical analyses showed that more pores and smaller grains were observed with increasing V5+ content, and the densification temperature of LCNV ceramics increased. Increased resistivity and negative temperature coefficient of resistance (TCR) and enhanced stability of impedance with frequency were also observed as the V5+ content increased. The electron density between Co and O weakened, and the DOS at EF decreased in the V-occupied structure. For the LCNV with x = 0.02 sintered at 1275 °C, a minimum resistivity of 1.06 mΩ cm was obtained, and the corresponding TCR was −1024 ppm/°C.