Microstructural and dielectric properties of Zr doped microwave sintered CaCu3Ti4O12 synthesized by sol-gel route

• Main Authors: Jesurani, Sinnappan, Kanagesan, Samikannu, Hashim, Mansor, Ismail, Ismayadi, Ibrahim, Idza Riati
• Format: Article
• Language: English
• Published: Hindawi Publishing Corporation 2014
• Online Access: http://psasir.upm.edu.my/id/eprint/52177/1/52177.pdf; http://psasir.upm.edu.my/id/eprint/52177/; https://www.hindawi.com/journals/amse/2014/187420/abs/
• Institution: Universiti Putra Malaysia

Polycrystalline samples with the chemical formula CaCu3 Ti 4 - x Zrx 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 m 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.