Structure–microwave property relations in (SrxCa(1−x))n+1TinO3n+1

The microwave dielectric properties of the (SrxCa(1−x))n+1TinO3n+1 series have been measured. When n=∞, a linear decrease in TCF from +1647 (SrTiO3) to 859 (CaTiO3) MK−1 was observed as Ca content increased. This trend in TCF was attributed to the onset of octahedral tilt transitions brought about by decreasing tolerance factor. Additions of excess SrO to SrTiO3 formed the Srn+1TinO3n+1 series with Q a maximum for Sr3Ti2O7. Ca substitutions to Sr3Ti2O7 resulted in a solid solution limited to the Sr and Ca rich ends of the (SrxCa1−x)3Ti2O7 series with Q a maximum of 10 250 at 2.5 GHz for Sr2.4Ca0.6Ti2O7 and TCF a minimum of 50 MK−1 for Ca3Ti2O7. The variation of TCF for the (SrxCa1−x)3Ti2O7 series was also attributed to the onset of octahedral tilt transitions.