Structural, thermoelectric, and magnetic properties of pure and Ti-doped Ca3Co4O9 ceramic compounds

Abstract

The effect of the Ti element on the incommensurately layered thermoelectric oxide material Ca3Co4O9 is investigated. In this study, the structural, morphological, thermoelectric, and magnetic properties of Ca3(Co3.7Ti0.3)O9 composition is compared to the pristine Ca3Co4O9. In the Ti-doped sample, no significant enhancement of the Seebeck coefficient compared to Ca3Co4O9 is observed. The magnetic properties of both the pristine and Ti-doped Ca3Co4O9 are detailed. In M-H measurements, the effect of Ti in low temperatures reveals a magnetic phase transition due to two sublattices exhibiting wavy behavior. For each sample, magnetic inhomogeneity in the long-range ferromagnetic ordering which is clear almost before 19 K is observed by means of FC and ZFC curves. The findings on the physical properties of both samples are discussed in light of the previously published results.