Structure, Dielectric Permittivity, and AC Conductivity of Cobalt and Lanthanum Doped TiO₂ Composites

Lanthanum doped titanium dioxide (La/TiO₂) was synthesized by a lengthy wet impregnation method with cobalt (Co/TiO₂). The prepared composites were characterized by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and scanning electron microscopy (SEM). The XRD spectrum of TiO₂ shows that the transition dopants are well dispersed within the TiO₂ matrix. The SEM images show no noticeable morphological differences between the TiO₂, La/TiO_2, and Co/TiO₂ composites. The dielectric properties and electrical of TiO₂, La/TiO_2, and Co/TiO₂ were investigated within temperature and frequency of 25–120 °C and 100 Hz to 0.3 MHz, respectively. It was noted that the dielectric constant decreases with increasing temperature. TiO₂ dielectric permittivity and electrical conductivity increased as a result of doping. In addition, the activation energy values for all samples were evaluated. By increasing frequency, activation energy values decreased and this decrease intensified when the Co ions are the substituents in the TiO₂ matrix. Otherwise, the values of activation energy are constant for La-dopedTiO_2.