Experimental and theoretical study on enhanced electrical properties of nickel-substituted La0.5Sr0.5CoO3-δ ceramics

Abstract The effect of Ni substitution on the thermal behavior, crystal structure, densification, and electrical properties of La0.5Sr0.5Co1–yNiyO3-δ (y = 0.00–0.08) (LSCN) ceramics was discussed based on experimental measurements and theoretical calculations to search for a ruthenium–free and lead–free conductive oxide for thick film resistors. Ceramics were synthesized by the solid–state reaction, and calculations were performed with first–principle density functional theory (DFT). Results showed that the replacement of Ni ion to Co ion could help decrease the densification temperature and enhance the densification level and improve the conductivity of LSCN. Theoretical calculations, including the crystal structure, bond population, total energy, and density of states (DOS), supported the experimental results well. The maximum conductivity of 3155 S/cm was achieved as y = 0.04 was sintered at 1200 ℃, and the peak temperature coefficient of resistance (TCR) of 2405.7 ppm/℃ occurred at y = 0.06.