For Barium Titanate Ceramics doped with the trivalent and hexavalent chromium oxides,the influence of Cr valence state on dielectric-temperature stability was investigated with Atomic force microscopy, X-ray diffraction, Raman spectroscopy, and dielectric measurements. The application of the trivalent Cr2O3 dopant can give rise to a temperature-stable X7R specification and a lower dielectric loss (< 0.02) when the sample was prepared at 1240 ºC, but the dielectric permittivity
is lower (~600); Cr ions exist predominantly as Cr4+ and slightly as Cr3+. Increasing sintering temperature will destroy the core-shell structure of the samples. The application of the hexavalent CrO3 dopant can not produce a temperature-stable X7R ceramic; Cr ions exist as Cr4+ and Cr5+. Cr5+ can not enter the perovskite lattice owing to the valence mismatching