Structural and electronic properties of the perovskite-type ferrimagnetic semiconductor CaCo0.5Zr0.5O3

The purpose of this work is to report the structural, magnetic, electrical and electronic properties of the perovskite-type semiconductor CaCo0.5Zr0.5O3. For the synthesis of the material, the standard solid-state reaction method was employed, followed by an analysis of its crystal structure by Rietveld refinement applied to X-ray diffraction patterns, which revealed the crystallisation of the compound in an orthorhombic structure belonging to the Pcmn space group. Through morphological and compositional analyses, it was determined that the surface of the samples evidenced mean grain size of 1.47 ± 0.01 µm, as well as the occurrence of minimal levels of impurities. The curves of magnetic susceptibility as a function of temperature and magnetisation as a function of external magnetic field showed a weakly ferrimagnetic response of the material, with Weiss temperature =-72 K and effective magnetic moment 1.78 B, suggesting that Co4+ does not present crystalline field splitting and the spins adopt low spin states. The electrical resistivity exhibits behaviour and order of magnitude (106 .m) characteristic of a semiconductor feature and current-voltage curves with a typical thermistor-type semiconductor response. Density of states and band structure analysis indicate that the material exhibits ferromagnetic semiconductor-like behaviour at low temperatures, with a mean band gap of 0.89 eV and an effective magnetic moment of 2.0 µB.