Details

Autor(en) / Beteiligte

• Zhang, Yun
• Zhang, Yingchun
• Fu, Baojian
• Hong, Ming
• Xiang, Maoqiao
• Liu, Zhiang
• Liu, Hui
• Liu, Shuya

Titel

Effects of pH on the crystal structure, morphology and microwave dielectric properties of Bi sub(12)TiO sub(20) ceramics synthesized by citrate sol-gel method

Ist Teil von

• Journal of materials science. Materials in electronics, 2015-05, Vol.26 (5), p.3179-3185

Erscheinungsjahr

2015

Quelle

SpringerLink

Beschreibungen/Notizen

• Bi sub(12)TiO sub(20) ceramics were prepared via a modified sol-gel route using citric acid as a metal chelating agent. The pH value of the initial precursor was adjusted from 6 to 13 by the addition of ammonium hydroxide (NH sub(4)OH). The effects of pH value on the formation of chelate complex between citric acid and metal ions were systematically investigated in this work. Furthermore, the crystal structure, microstructure and microwave dielectric properties of Bi sub(12)TiO sub(20) ceramics derived at various pH values were characterized. Scanning electron microscopy and energy dispersive spectroscopy indicated that a single Bi sub(12)TiO sub(20) phase with high relative densities above 96 % of the theoretical density was successfully achieved at pH 11. The variations in density, ionic polarizability and microstructure had a remarkable effect on the microwave dielectric properties of Bi sub(12)TiO sub(20) ceramics. In the case of pH 11, Bi sub(12)TiO sub(20) ceramics sintered at 750 degree C exhibited promising microwave dielectric properties: epsilon r = 39.55, Q f = 3950 GHz, and tau f= - 17 ppm/ degree C, indicating that they were promising dielectric candidates for LTCC applications.