Polycrystalline samples with the chemical formula CaCu3Ti4?xZrxO12 (x = 0, 0.02, 0.1, 0.2, 0.5, and 0.1) CCTZO were synthesized\nfrom metal nitrate solutions by the sol-gel method, followed by conventional and microwave heat treatments. The X-ray diffraction\npattern of powder calcined at 800?C in conventional furnace for 3 h showed formation of a single phase. The crystal structure did\nnot change on doping with zirconium and it remained cubic in the five studied compositions. The surface morphology of samples\nsintered at 1000?C in microwave furnace for 10 min was observed using a high resolution scanning electron microscope (HR-SEM).\nThe grain sizes were in the range of 250 nmââ?¬â??5 ?m for these samples. HRSEM results show that doping with Zr enhanced grain\ngrowth or densification. Energy dispersive X-ray spectroscopy (EDX) confirmed the presence of Zr.The dielectric characteristics\nof Zr doped CCTO were studied with an LCR meter in the frequency range of 50Hzââ?¬â??1MHz. A very high dielectric constant 21,500\nwas observed for the sample doped with Zr (0.02mol%) at 50Hz.
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