Synthesis and characterization of new doped dielectric materials based on CaCu3Ti4O12 (CCTO) applied at high temperature

Abstract

In this study, we explored the impact of La3+/Nd3+ substitutions on the microstructure and dielectric characteristics of Ca0.9(La1-yNdy)0.066Cu3Ti4O12 ceramics (with varying y values: 0.25, 0.5, and 0.75). The X-ray diffraction (XRD) analysis confirmed that the synthesized samples exhibited a cubic perovskite structure (Im-3 space group) without any discernible impurities. Examination of the samples using scanning electron microscopy (SEM) unveiled that the introduction of small amounts of La3+/Nd3+ during sintering led to a reduction in the grain size of CCTO. Dielectric assessments demonstrated that all the solid-state samples containing dopants displayed remarkable dielectric permittivity (ε'>3 × 103) across a wide spectrum of frequencies up to 1 MHz and various temperatures (Δε'/ε′20< ±15 %). This study lays the groundwork for the development of novel dielectric materials based on CCTO, specifically suited for applications at temperatures exceeding room temperature. Furthermore, the ceramic doped with y = 0.5 also exhibited low dielectric loss, with a tanδ value of approximately 0.02 at 60 °C and 1 kHz.