EPMA and microstructural characterization of yttrium doped BaTiO3 ceramics

Yttriurn-doped BaTiO3 ceramics have been studied as a potential material fo r positive temperature coefficient resistors (PTCR). The mechanism of Y inc orporation into BaTiO3 plays an important role for displaying good electric al properties. Determination of the amount of yttrium in the BaTiO3 as well as microstructure characterization of the samples were pet performed using SEMI EDS and WDS analysis. An optimized trace element WDS quantitative ana lysis was applied to determine elemental concentrations for Ba, Ti and Y in the samples as accurately as possible. BaTiO3 and Y2O3 were used as standa rds. Analysis was undertaken using a JEOL JXA 840A electron probe microanal yzer WDS X-ray intensity measurements were performed under 20kV, 50nA beam current and 0.2% preset standard counting deviation (sigma(c)) using a PET crystal. Measured k-ratios were quantified by ZAF matrix correction. Averag e results of WDS quantitative analysis showed 20.17 +/- 0.08 at % Ti, 19.95 +/- 0.09 at % Ba, 0.22 +/- 0.03 at % Y, and 59.66 at % O. The results sugg est incorporation of yttrium in the BaTiO3 preferentially at the Ba-sites, however partial incorporation of Y at Ti-sites could not be excluded.