Preparation and characterisation of the Ba(Zr,Ti)O3 ceramics with relaxor properties

Ba(ZrxTi1-x)O3 ceramics with x = 0.10, 0.15 and 0.18 were prepared via solid state reaction. For the composition x = 0.10, ceramics with various grain sizes in the range 0.75-3.20 µm were obtained by sintering at various temperatures 1350-1500 °C. High permittivity (above 14,000 at the transition temperature) and losses smaller than 7% for temperatures below 120 °C, together with a shift of the Curie temperature towards lower values with increasing x, are characteristic to these ceramics. A ferroelectric-relaxor crossover takes place when x increases, with intermediate character for all the compositions. For the composition x = 0.10, the relaxor state is favoured by reducing the grain size.