Microwave Quality Factor of Cation-Deficient Perovskites Ba(M2+ 1/3Nb2/3)O3

Non-linear variation of the microwave quality factor (Q) of both A-site and B-site cation deficient perovskites Ba(M2+ 1/3Nb2/3)O3 (M2+ = Mg, Co, Zn) have been discussed and summarized. Within the homogeneity regions, the observed increase in the Q-factor was attributed to the improvement of either ceramics’ densification or 1:2 cation ordering. Out of the homogeneity limits, the changes in the Q-magnitude were shown to depend on the type of main impurity phase: either Ba9M2+Nb14O45 (A-site deficiency) with the tetragonal tungsten bronze structure or Ba8M2+Nb6O24 (B-site deficiency) - hexagonal perovskite.