Effective use of alternative energy requires high capacity energy storage technology for many applications. This requires the development of materials with high dielectric constant combined with low dielectric losses. Calcium copper titanate (CaCu3Ti4O_(12); CCTO) high-k dielectrics are attractive for energy storage applications because of high dielectric constants in the range of 10~4 - 10~5. Solid-state processing techniques to prepare CaCu3Ti_(4-x)Al_xO_(12-x/2) (x=0, 0.06, 0.1, and 0.5), which will enable effective mitigation of dielectric losses will also be described. X-ray diffraction (XRD) studies of the synthesized samples show that it is possible to synthesis phase pure CCTO by simple solid-state method at relatively low calcination temperature (850 °C). Therefore, Al-doping was done in the form of aluminum nitrate into calcined pure-CCTO and re-calcined at 850 °C. Microstructure observations by scanning electron microscopy (SEM) showed relatively homogeneous microstructure for the sintered samples in the range of 1050 - 1080 °C. Density measurements of pure-CCTO showed the highest density at 1060 °C and hence Al-doped samples were also sintered at the same temperature. No Al-containing phase could.be seen by XRD in Al-doped CCTO calcined powders as well as ceramics (as-sintered and polished) indicates substitution of Al~(+3) for Ti~(+4) as there is no Al containing phases in the Al doped CCTO up to x=0.5. However, small CuO phase seen by XRD patterns of as-sintered specimen indicated partial re-oxidation of CUO/CU2O.
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