The defect structure, sintering behavior, and dielectric responses of [Cr.sub.2][O.sub.3]-doped [Sr.sub.0.5][Ba.sub.0.5][Nb.sub.2][O.sub.6]

The structural variations of undoped and [Cr.sub.2][O.sub.3]-doped [Sr.sub.0.5][Ba.sub.0.5][Nb.sub.2][O.sub.6] (SBN) are investigated along with the isothermal sintering behavior by using the x-ray diffractometer. The maximum dielectric constant ([epsilon.sub.max]) is determined by the competition between the reduction of the polarization due to the substitution of Cr for Nb and the enhancement of the polar moment arising from the weakening of Nb-O bonds due to the creation of the oxygen vacancies.