Abstract
As a microwave dielectric. BaTi4O9 is profitable for its high Q value, however, it is disadvantageous for its high temperature coefficient.
In our investigation reported here, we used ZnO-Ta2O5 system compounds said to own negative temperature coefficient, added them to BaTi4O9 and studied the effects.
Results obtained are summarized as follows:
(1) The addition of ZnO and Ta2O5 to BaTi4O9 improved both the Q value and temperature coefficient, and the best composition obtained were regarded thus; BaO:17.50mol%, TiO2:70.00mol%. Ta2O5:0.75mo1% and ZnO:11.75mol%.
(2) We observed black part with poor Zn and white part with rich Zn in the structure both in the center and on the surface of sintered specimen above mentioned, and it was confirmed that the structure in the center was more coarsened than that on the surface, comparatively.
(3) Adding Mn2O3 to BaTi4O9. we obtained identical structure in the center and on the surface, with the Q value and temperature coefficient both improved. It is confirmed that the most suitable amount of Mn2O3 to add is 0.18mol%, in this occasion.
