The shell thickness of a BaTiO3 ceramic with a core–shell structure has been measured by means of synchrotron X‐ray diffraction (XRD). BaTiO3 ceramic is known from transmission electron microscope (TEM)/energy dispersive X‐ray spectroscopy (EDS) observations to have an inhomogeneous microstructure with cores of a pure BaTiO3 and shells doped with additives. It is also known, from XRD observations, that the BaTiO3 cores have a tetragonal lattice structure and the shells are pseudocubic. We have estimated the shell thickness d from the full‐width at half‐maximum (FWHM) of the cubic (400)c peak, using Scherrer's equation. The shell thickness dcal was also evaluated from the volume fraction of tetragonal BaTiO3 using a spherical core–shell model. The two values thus determined agree well, confirming that the BaTiO3 ceramic specimens have a core–shell structure. Our results show that synchrotron XRD is a simple and effective tool for quantitative analysis of the core–shell structure. It enables us to understand quantitatively the relationship between the microstructure and the dielectric properties of BaTiO3 ceramics.

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The crystallinity of multicomponent glass-ceramic mixtures has been analyzed via the Rietveld method, using powder X-ray diffractometry data. The Rietveld technique uses an internal standard but requires no calibration data to determine the total amorphous phase content of a mixture. This method of analyzing the crystallinity of synthetic mixtures gives high-precision results, with an error of generally less than ±3.0%, for several glass-ceramics.

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