1. Grain Growth Behavior and Electrical Properties of 0.96(K 0.46-x Na 0.54-x )Nb 0.95 Sb 0.05 O 3 -0.04Bi 0.5 (Na 0.82 K 0.18 ) 0.5 ZrO 3 Ceramics.
- Author
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Park YJ, Yoo IR, Choi SH, Cho J, and Cho KH
- Abstract
This study investigated the causes of microstructural changes and the resultant electrical properties according to the sintering temperature of 0.96(K
0.46-x Na0.54-x )Nb0.95 Sb0.05 O3 -0.04Bi0.5 (Na0.82 K0.18 )0.5 ZrO3 lead-free ceramics by analyzing the correlation between vacancy concentrations and 2D nucleation. When sintered for 4 h, no grain growth occurred for the x = 0.000 composition over a wide temperature range, demonstrating that the existence of initial vacancies is essential for grain growth. As x increased, that is, as the vacancy concentration increased, the critical driving force (ΔGC ) for 2D nucleation decreased, and abnormal grain growth was promoted. The number and size of these abnormal grains increased as the sintering temperature increased, but at sintering temperatures above 1100 °C, they decreased again owing to a large drop in ΔGC . The x = 0.005 specimen sintered at 1085 °C exhibited excellent piezoelectric properties of d33 = 498 pC/N and kp = 0.45 due to the large number of large abnormal grains with an 83% tetragonal phase fraction. The x = 0.000 specimen sintered at 1130 °C with suppressed grain growth exhibited good energy storage properties because of its very high relative density and small grain size of 300 to 400 nm.- Published
- 2022
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