Polymorphic phases of Bi2(Zn1/3Ta2/3) 2O7 pyrochlore were studied. A metastable monoclinic structure was observed at temperatures below 950°C. This low-temperature phase possesses highly temperature-stable characteristics in the microwave frequency range (5-7 GHz) with a temperature coefficient of resonant frequency (τf) = -8.8ppm/°C. The addition of B2O 3 to Bi2(Zn1/3Ta2/3) 2O7 significantly lowered the sintering temperature, to 850°C, without an associated structural transition. Low-temperature sintering mechanisms have been investigated using dilatometry and transmission electron microscopy. Bi2(Zn1/3Ta2/3) 2O7 with 0.5 wt% B2O3 can be suitable for application in low-temperature cofired ceramics (LTCC), due to its reduced sintering temperature and good microwave dielectric properties: quality factor (Q × f) = 3500 GHz at 6.7 GHz, dielectric constant (ε r) = 63.9 and τf = -14.1 ppm/°C.
|Number of pages||4|
|Journal||Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers|
|Publication status||Published - 2003 Aug 1|
- Microwave dielectric properties
ASJC Scopus subject areas
- Physics and Astronomy(all)