Structural, dielectric, electrical, and optical properties of the Ca3CuTi4O12 ceramic

In this communication, the synthesis of the Ca3CuTi4O12 (CCTO) ceramic by a conventional solid-state reaction method is reported. The XRD analysis confirms an orthorhombic structure with average crystallite size and lattice strain are about 96.5 nm and 0.116% respectively. Field emission scanning electron microscope (FESEM) analysis confirms both weight and atomic percentage of all constituent elements and agglomeration rate of grains (D-SEM /D-SC = 7.4); which may be a possible reason for the observed elevated dielectric constant. No trace of phase transition is observed from the Raman lines; so, the observed giant dielectric constant may not be related to the displacement of Ti ions. The energy bandgap is about 3.72 eV, which may suitable for photovoltaic applications. The semiconducting nature is confirmed from the both Nyquist and Cole-Cole plots. Thermistor constant (beta), sensitivity factor (alpha), and stability factor of the sample were calculated; which confirms the characteristics of the NTC thermistor.