Structural, dielectric and electrical properties of lead cadmium tungstate ceramics

Polycrystalline samples of Pb(Cd1/2W1/2)O3 were synthesized by a high-temperature solid-state reaction technique. Preliminary crystal structure and microstructure of the compound at room temperature were studied using X-ray diffraction (XRD) technique and scanning electron microscopy (SEM), respectively. The dielectric permittivity (ε) and loss tangent (tan δ) of the compound were obtained both as a function of frequency (103–104 Hz) at room temperature and temperature (30–320°C) at 10 kHz. Both the ac and dc conductivity has been studied over a wide range of temperature. The activation energy (Ea) of the compound was calculated from the plot of ac conductivity versus inverse of absolute temperature. The temperature variation of resistivity shows that the compound has positive temperature coefficient of resistance (PTCR). The current–voltage (I–V)-characteristics of the compound studied at diffierent temperatures reveals that the compound also has excellent varistor behavior.