Microstructural and Dielectric Properties of Zr Doped Microwave Sintered C a C u 3 T i 4 O 12 Synthesized by Sol-Gel Route

Abstract EN

Polycrystalline samples with the chemical formula CaCu3 Ti 4 - x Zr x O12 ( x = 0 , 0.02, 0.1, 0.2, 0.5, and 0.1) CCTZO were synthesized from metal nitrate solutions by the sol-gel method, followed by conventional and microwave heat treatments.

The X-ray diffraction pattern of powder calcined at 800°C in conventional furnace for 3 h showed formation of a single phase.

The crystal structure did not change on doping with zirconium and it remained cubic in the five studied compositions.

The surface morphology of samples sintered at 1000°C in microwave furnace for 10 min was observed using a high resolution scanning electron microscope (HR-SEM).

The grain sizes were in the range of 250 nm–5 μm for these samples.

HRSEM results show that doping with Zr enhanced grain growth or densification.

Energy dispersive X-ray spectroscopy (EDX) confirmed the presence of Zr.

The dielectric characteristics of Zr doped CCTO were studied with an LCR meter in the frequency range of 50 Hz–1 MHz.

A very high dielectric constant 21,500 was observed for the sample doped with Zr (0.02 mol%) at 50 Hz.