Sintering behavior and physical properties of Bi0.5(Na1–xKx)0.5SnO3 lead-free ceramics

• Main Authors: Nguyen Truong Tho, Le Ngoc Minh, Le Tran Uyen Tu, Dung Thi Hoai Trang, Le Phuoc Dinh, Nguyen Ly Huu Huan, Le Thi Phuong Thao, Nguyen Thi Hue, Ngo Minh Hau
• Format: Article
• Language: English
• Published: HUJOS 2021-06-01
• Series: Tạp chí Khoa học Đại học Huế: Khoa học Tự nhiên
• Subjects: Lead-free ceramics; BNKS; electromechanical coupling factor; sintering; dielectric constant
• Online Access: http://jos.hueuni.edu.vn/index.php/hujos-ns/article/view/6191

In this study, Bi0.5(Na1–xKx)0.5SnO3 (BNKS) ceramics (x = 0, 0.1, 0.2, 0.3, and 0.4) were fabricated via ultrasound wave before milling. The time of ball milling decreased from 20 to 1 h. The X-ray diffraction patterns show that the BNKS has a single-phase structure. When the potassium content increases, the phase structure of the ceramics changes from rhombohedral to tetragonal. When sintered at 1100 °C and x = 0.2, the ceramics’ physical properties are the best with the mass density of 5.59 g/cm3, the electromechanical coupling constants kp of 0,31 and kt of 0.27, the remanent polarization of      11.9 µC/cm; the dielectric constant εr of 1131, and the highest dielectric constant emax of 4800.