P. Thomas, R. S. Ernest Ravindran, K. B. R. Varma
Composites comprising Poly(Methyl Methacrylate) (PMMA) and CaCu3Ti4O12 (CCTO) via melt mixing followed by hot pressing were fabricated. These were characterized using X-ray diffraction (XRD), thermo gravimetric (TGA), scanning electron microscopy (SEM) and Impedance analyser for their structural, morphology and dielectric properties. Composites were found to have better thermal stability than that of pure PMMA. The composite, with 38 Vol % of CCTO (in PMMA), exhibited remarkably low dielectric loss at high frequencies and the low frequency relaxation is attributed to the space charge polarization MWS effect. Theoretical models were employed to rationalise the dielectric behaviour of these composites. At higher temperatures, the relaxation peak shifts to higher frequencies, due to the merging of both {beta} and {alpha} relaxations into a single dielectric dispersion peak. The AC conductivity in the high frequency region was attributed to the electronic polarization
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http://arxiv.org/abs/1301.4077
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