Löhnert, RomySchmidt, RainerTöpfer, Jörg2023-06-182023-06-182015-061385-344910.1007/s10832-015-9982-0https://hdl.handle.net/20.500.14352/24315© Springer International Publishing AG. This work was supported by the State of Thuringia, Germany, through a grant in the ProExzellenz network (Kerfunmat, PE214). R.S. wishes to acknowledge a Ramón y Cajal fellowship from the MICINN/MINECO (Spain).The influence of sintering temperature and dwell time on the microstructure formation and dielectric properties of CaCu_(3)Ti_(4)O_(12) ceramics was investigated. For sintering temperatures of 1050 and 1100 °C significant differences in the CaCu_(3)Ti_(4)O_(12) ceramic microstructure and the segregation of a CuO_(x)-rich phase towards the grain boundary (GB) areas were observed with increasing dwell time. In addition to the formation of a semiconducting bulk and insulating grain boundary phase the segregated CuO_(x) forms an intergranular phase, and the effects of this phase on the dielectric properties are rather intriguing. At sintering temperature below 1050 °C only small amounts of CuO_(x) segregate, whereas sintering above 1050 °C (e.g., 1100 °C) leads to increased evaporation of the CuO_(x). Therefore, the effects of the CuOx-rich intergranular phase upon the dielectric properties are felt strongest in samples sintered at 1050 °C. Such effects are discussed in terms of microstructural variations due to liquid phase sintering behavior facilitated by the TiO_(2)-CuO_(x)-eutectic, which appearsto be melted at high sintering temperature prior to evaporation of CuO_(x) at prolonged dwell times at the highest sintering temperatures(1100 °C).engjournal articlehttp://dx.doi.org/10.1007/s10832-015-9982-0http://link.springer.com/open access537Barrier layer capacitorConstantClues.ElectricidadElectrónica (Física)2202.03 Electricidad