Dielectric and mechanical characteristics of lanthanum aluminate ceramics with strontium niobate addition

• Published in: Journal of the European Ceramic Society Vol. 24; no. 7; pp. 1999 - 2004
• Main Authors: Liu, X.Q., Chen, X.M.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.01.2004; Elsevier
• Subjects: Applied sciences; Building materials. Ceramics. Glasses; Ceramic industries; Chemical industry and chemicals; Dielectic properties; Electrotechnical and electronic ceramics; Exact sciences and technology; LaAlO 3; Mechanical properties; Sr 2Nb 2O 7; Technical ceramics; Mechanical properties; Sr 2Nb 2O 7; Dielectic properties; LaAlO 3; Grain size; Strontium Diniobates; Scanning electron microscopy; Aluminium Lanthanum Oxides Mixed; Electrical properties; Dielectric properties; Experimental study; Oxide ceramics; Structure composition relationship; Lanthanum oxide; Fracture toughness; Lanthanide compound; Additive; Aluminium Oxides; Manufacturing; Microstructure; Permittivity; Electroceramics
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/S0955-2219(03)00372-8

The microstructures, microwave dielectric properties and mechanical properties were investigated for LaAlO 3 ceramics with Sr 2Nb 2O 7 additive. The grain size decreased significantly when the additive was introduced, and the Sr 2Nb 2O 7 reacted with the LaAlO 3 ceramic matrix to form a LaNbO 4 secondary phase. The dielectric constant varied slightly, while the Qf value increased at first and then decreased when the additive content passed a critical value. The effects of the Sr 2Nb 2O 7 additive upon the temperature coefficient of resonant frequency were dependent on the sintering conditions. The fracture toughness was significantly improved by Sr 2Nb 2O 7 addition.