(1-x)ZnNb2O6·xTiO2 ceramics were prepared using both anatase and rutile forms of TiO2. At a composition of x = 0.58, a mixture region of ixiolite (ZnTiNb2O8) and rutile was observed and the temperature coefficient of resonant frequency (τf) was ∼0 ppm/°C. We found that although εr and τf were comparable, the quality factor (Q × f, Q ≈ 1/tan δ,f = resonant frequency) of 0.42 ZnNb2O6·0.58 TiO2 prepared from anatase and rutile was 6000 and 29 000, respectively. The origin of the difference in Q × f of both samples was investigated by measuring electrical conductivity and by analysis of the anatase-rutile phase transition. The anatase-derived sample had higher conductivity, which was related to the reduction of Ti4+. It is suggested that the increase of dielectric loss originates from an increase in Ti3+ and oxygen vacancies due to an anatase-rutile phase transition.
|Number of pages||4|
|Journal||Journal of the American Ceramic Society|
|Publication status||Published - 2002 May|
ASJC Scopus subject areas
- Ceramics and Composites
- Materials Chemistry