Abstract:
By substituting F
- for O
2-, Bi
1.5-xCa
xZnNb
1.5O
7 (0.00≤
x≤0.30, abbreviated as C-
x), Bi
1.5-xCa
xZnNb
1.5O
7-yF
y (0.00≤
x≤0.20, abbreviated as CF-
x) ceramics samples were prepared by conventional solid-state reaction method. The way of defect compensation, doping position substitution position, the influence of F
- dopant on phase structure, crystal chemistry and dielectric properties of Ca-doped Bi
1.5ZnNb
1.5O
7 (abbreviated as α-BZN) ceramics samples were investigated. The results revealed that F
- incorporation declined the solid solution of Ca
2+ in α-BZN, and F
- was dissolved into the oxygen site of BO
6 octahedral. In the same amount of Ca
2+ dopant, with F
- incorporation, both the dielectric constant and the dielectric loss decreased, which was consistent to the bond valence sums for A
4O′. Compared with Ca
2+ doping, the bond valence sums for A
4O′ of F
- and Ca
2+ co-doping increased. The shift of the dielectric constant peak to higher temperature could be associated with the increase in activation energy due to the addition of F
-.