X-Ray Investigations and Determination of the Dielectric Properties of the Compound Ba4.5Gd9Ti18O54
- 1 January 1996
- journal article
- Published by IOP Publishing in Japanese Journal of Applied Physics
- Vol. 35 (1R)
- https://doi.org/10.1143/jjap.35.144
Abstract
The composition of the Gd variant of the Ba6- x R8+2/3 x Ti18O54 family of solid solutions ( R=rare earth) was determined by investigating its high temperature phase relations and by wavelength-dispersion spectroscopic analysis. The composition of the compound was determined to be Ba4.5Gd9Ti18O54, which corresponds to x=1.5 without a detectable solid solubility range. The intensities of the diffraction lines are not in accordance with published values in the powder diffraction file (No. 43–233). An investigation of the thermal stability revealed that Ba4.5Gd9Ti18O54 starts to decompose at a temperature around 1350° C. It decomposes into a Gd2Ti2O7, BaTi2O5 solid solution with Gd2O3, and probably Ba4Ti13O30. However, during slowly cooling metastable BaTi2O5(ss) also decomposes into Ba6Ti17O40 and BaTiO3 solid solution with Gd2O3. Single phase Ba4.5Gd9Ti18O54 ceramics displayed a dielectric constant (ε r) of 76.1, a Q x f-value of 2050 and a temperature coefficient of the resonant frequency (τ f) of -35 ppm/K.Keywords
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