Thermal behavior of La3+, Ni2+ and Sn4+ co-doped CaCu3Ti4O12 ceramics dielectric response

Abstract

Dielectric properties control by elements co-doping is important research problem for application of ceramics based on CaCu3Ti4O12 (CCTO) as a component of electronic devices. In this work, the effect of La3+, Ni2+ and Sn4+ co-doping on the dielectric properties of CCTO ceramics, including their thermal stability, was investigated. Solid solutions with compositions of Ca1-xLa2x/3Cu2.95Ni0.05Ti3.7Sn0.3O12 (x = 0.010–0.055), Ca0.94La0.027Cu3-yNiyTi3.7Sn0.3O12 (y = 0.020–0.065), Ca0.94La0.027Cu2.95Ni0.05Ti4-zSnzO12 (z = 0.25–0.4) were synthesized by the solid-state method at 970 °C. The incorporation of doping elements into the ceramic structure after sintering at 1080 °C was confirmed by X-ray diffraction data. Grain morphology and size of various solid solutions were estimated from scanning electron microscopy photographs. The optimal concentrations of doping elements were x = 0.04, y = 0.05, and z = 0.3, which is evident by high permittivity ε′ = 11,000 and low dielectric losses tanδ = 0.051 at f = 1 kHz. La3+, Ni2+ and Sn4+ co-doped CCTO ceramics demonstrated high stability of the permittivity in the temperature range from −60 to +125 °C. Based on the demonstrated dielectric properties, the presented solid solutions are suitable for use in ceramic capacitors.