COMPARISON OF GRAIN SIZE EFFECTS ON MICROSTRUCTURE AND DIELECTRIC PROPERTIES OF Y2/3Cu3Ti4-xFe_xO_(12) (X = 0.00, 0.05 AND 0.15) CERAMICS SYNTHESIZED BY GLYCINE ASSISTED SEMI WET ROUTE

摘要

The Precursor powder of Y_(2/3)Cu3Ti_(4-x)Fe_xO_(12) ceramics (x= 0.00, 0.05, 0.15) were fabricated by semi-wet route using metal nitrate solution and solid TiO2 powder at a relatively lower sintering temperature 950 °C. The effects of Fe~(3+) doping at different concentration level upon the microstructure and dielectric properties of yttrium copper titanate ceramics (YCTO) have been studied over the temperature and frequency range 35-950 °C and 2Hz-5MHz, respectively. The heterovalent doping of Fe~(3+) on Ti~(4+)-site in the YCTO ceramics resulted into an appreciable decrease in the grain size and dielectric constant but a significant lowering of dielectric loss was observed. The loss tangent (tanδ) of Y_(2/3)Cu3Ti_(4-x)Fe_xO_(12) (x = 0.15) ceramic drops to 0.58 at a frequency of 1 KHz, which is reduced by 19% in comparision to pure CCTO ceramic. The origin of dielectric dispersion phenomena in iron doped YCTO ceramic has been discussed.