Study of LaCoO3 Across Insulator–Metallic Phase Transition

The standard solid-state reaction method was used to prepare perovskite LaCoO3 crystal successfully. The crystal structure was confirmed by means of powder X-ray diffraction. An investigation of the electrical properties shows an interesting temperature dependence. The real and imaginary parts of the dielectric constant show maximum at 533 K and minimum at 548 K. This indicates an Insulating-Metallic phase transition. It was found that the activation energy \(\Delta E_{a}\) in the semiconducting region was about 0.80 eV. The grain resistance shows an inverse dependence on temperature justify negative temperature coefficient of resistance exhibit. The crystal exhibits non-Debye type dielectric relaxation.