Structure-microwave property relations of Ca and Sr titanates

The microwave dielectric properties of the SrxCa1-xTiO3, Srn+1TinO3n+1 and (SrxCa1-x)(3)Ti2O7 series have been measured. TCF decreases from + 1647 to + 859 MK-1 as Ca content increases in the SrxCa1-xTiO3 series, due to the o nset of octahedral tilt transitions. Additions of excess SrO to SrTiO3 form the Srn+1TinO3n+1 series with Q a maximum for Sr3Ti2O7, Ca substitutions t o Sr3Ti2O7 result in a solid solution limited to the Sr and Ca rich ends of the (SrxCa1-x)(3)Ti2O7 series with Q a maximum of 10 250 at 2.5 GHz for Sr 2.4Ca0.6Ti2O7 and TCF a minimum + 50 MK-1 for Ca3Ti2O7. The variation of TC F for the (SrxCa1-x)(3)Ti2O7 series was also attributed to the onset of oct ahedral tilt transitions. (C) 2001 Published by Elsevier Science Ltd. All r ights reserved.