Additive Sintering, Postannealing, and Dielectric Properties of SrTaO2N. Issue 4 (31st January 2014)

• Record Type: Journal Article
• Authors: Sun, Shi‐Kuan; Zhang, Ya‐Ru; Masubuchi, Yuji; Motohashi, Teruki; Kikkawa, Shinichi; Troiler‐McKins, S.
• Is Part Of: Journal of the American Ceramic Society. Volume 97:Issue 4(2014)
• Page Start: 1023
• Page End: 1027
• Publication Date: 2014-01-31
• Subjects: Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.12806
• Languages: English
• ISSNs: 0002-7820

Abstract

<abstract abstract-type="main" id="jace12806-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>The maintaining of the chemical composition and electrical insulativity of SrTaO<sub>2</sub>N ceramics was investigated during sintering and annealing, using powders prepared by the nitridation of Sr<sub>2</sub>Ta<sub>2</sub>O<sub>7</sub>. Due to the low thermal stability of SrTaO<sub>2</sub>N, the partial loss of SrO and nitrogen induced the formation of a TaO<sub>0.9</sub> impurity after heat‐treating at above 1100°C. The sintering additive SrCO<sub>3</sub> and postannealing in NH<sub>3</sub> were employed to compensate for the loss of SrO and nitrogen to obtain ceramics with the original chemical composition. The as‐sintered SrTaO<sub>2</sub>N ceramics with various relative density (<italic>RD</italic>) were annealed in NH<sub>3</sub> to observe the recovery of color and electrical insulativity. It was found that the inner part of the well‐sintered samples with <italic>RD</italic> = 95.1% could not be recovered by annealing, and continued to exhibit semiconducting behavior and a black color. On the other hand, for the as‐sintered SrTaO<sub>2</sub>N ceramics with <italic>RD</italic> < 84%, both the nitrogen content and electrically insulating behavior were completely recovered after annealing. The postannealed SrTaO<sub>2</sub>N ceramics (<italic>RD</italic> = 83.3%) possessed a relatively large dielectric constant of 450 with a low dielectric loss of less than 0.1 at 100 Hz, almost independent of frequency and temperature.</p> </abstract>