Low‐Fire Processing of Microwave BNBT‐Based High‐k Dielectric with Li2O–ZnO–B2O3 Glass. Issue 12 (18th October 2013)

• Record Type: Journal Article
• Authors: Shih, Yi‐Ting; Jean, Jau‐Ho; Damjanovic, D.
• Is Part Of: Journal of the American Ceramic Society. Volume 96:Issue 12(2013)
• Page Start: 3849
• Page End: 3856
• Publication Date: 2013-10-18
• Subjects: Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.12602
• Languages: English
• ISSNs: 0002-7820

Abstract

<abstract abstract-type="main" id="jace12602-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>The effects of Li<sub>2</sub>O–ZnO–B<sub>2</sub>O<sub>3</sub> (LZB) glass addition on densification and dielectric properties of Ba<sub>4</sub>(Nd<sub>0.85</sub>Bi<sub>0.15</sub>)<sub>9.33</sub>Ti<sub>18</sub>O<sub>54</sub> (BNBT) have been investigated. At a given ratio of ZnO/B<sub>2</sub>O<sub>3</sub>, the glass softening point decreases, but the thermal expansion coefficient and dielectric constant increase with increasing Li<sub>2</sub>O content in the LZB glass. With 10 vol% LZB glass, the densification temperature reduces greatly from 1300°C for pure BNBT to 875°C–900°C for BNBT + LZB dielectric, and the densification enhancement becomes more significant with increasing Li<sub>2</sub>O content in the LZB glass. The above result is attributed to a chemical reaction taking place at the interface of LZB/BNBT during firing, which becomes less extensive with increasing Li<sub>2</sub>O content in the LZB glass. Therefore, more residual LZB glass, which acts as a densification promoter to BNBT, is left with increasing Li<sub>2</sub>O content. For the LZB glass with a Li<sub>2</sub>O content in the range 10–30 mol%, the resulting 90 vol% BNBT + 10 vol% LZB microwave dielectric has a dielectric constant of 55–70, product (<italic>Q × f</italic><sub>r</sub>) of quality factor (<italic>Q</italic>) and resonant frequency (<italic>f</italic><sub>r</sub>) of 1000–3000 GHz at 5–5.79 GHz, and a temperature coefficient of resonant frequency (τ<sub>f</sub>) of 10–60 ppm/°C in the temperature range between 25°C and 80°C.</p> </abstract>