Preparation and Dielectric Properties of K1/2Na1/2NbO3 Ceramics Obtained from Mechanically Activated Powders

Materials

Dariusz Bochenek¹  Diana Szalbot¹  Małgorzata Adamczyk-Habrajska¹  Jolanta Dzik¹  Izabela Szafraniak-Wiza² 

[1] Faculty of Science and Technology, University of Silesia, Institute of Materials Engineering, 12, Zytnia Str., 41-200 Sosnowiec, Poland;Institute of Materials Science and Engineering, Poznań University of Technology, Jana Pawła II 24, 61-138 Poznań, Poland;

关键词: lead-free materials;    perovskites;    mechanical activation;    potassium sodium niobate;    dielectric properties;   

DOI  :  10.3390/ma13020401

来源: DOAJ

【 摘 要 】

Alkaline based materials have been considered as a replacement for environmentally harmful Pb(Zr,Ti)O₃ (PZT) electro-ceramics. In this paper, the K_1/2Na_1/2NbO₃ (KNN) ceramics were prepared in a three stage process: first Nb₂O₅, Na₂CO_3, and K₂CO₃ were milled in a high energy mill (shaker type) for different periods, between 25 h and 100 h, consecutively a solid state reaction was carried out at 550 °C. Finally, the uniaxially pressed samples were sintered at 1000 °C. The reaction temperature is lower for mechanically activated powders than in the case of the conventional solid-state method. The ceramic samples, prepared from the mechanically activated powders, were investigated by dielectric spectroscopy. The influence of the duration of the mechanical activation on the properties of the ceramic materials, e.g., ceramic microstructures, phase transition temperatures, character of the temperature dependences of dielectric permittivity, are discussed.

【 授权许可】

Unknown