Effects of Sintering Atmosphere on Electrical Properties of (1−x)(K_0.5Na_0.5)NbO₃-xAgNbO₃ Ceramics

Abstract

Effects of sintering atmosphere on the electrical properties of (1−x)(K_0.5Na_0.5)NbO₃-xAgNbO₃ (0 ≤ x ≤ 0.2) were investigated. With reducing atmosphere, the unit-cell volume of the specimens with perovskite structure was decreased, and the solid solution range was decreased. The grain size of the specimens was not only affected by an AgNbO₃ content, but also the sintering atmosphere. Within the solid solution range, the electromechanical coupling factor (k_p ), piezoelectric constant (d₃₃ ) and dielectric constant (ϵ_r) of the specimens were increased with increasing of AgNbO₃ content and/or reducing atmosphere. The mechanical quality factor (Q_m ) of the specimens was depended on the relative density of the specimens.

Keywords:

• Lead-free ceramics
• Microstructure
• Electrical properties
• Sintering atmosphere
• AgNbO₃

Acknowledgments

This research was supported by a grant from the Fundamental R&D Program for Core Technology of Materials funded by the Ministry of Knowledge Economy, Republic of Korea.