1. 1 Y. Saito , H. Takao , T. Tani , T. Nonoyama , K. Takatori , T. Homma , T. Nagaya , and M. Nakamura , “Lead-Free Piezoceramics,” Nature, 432, 84-7 (2004).
2. 2 M. D. Maeder , D. Damjanovic , and N. Setter , “Lead-Free Piezoelectric Materials,” J. Electroceram., 13, 385-92 (2004).
3. 3 Z. S. Ahn and W. A. Schulze , “Conventionally Sintered (Na0.5K0.5)NbO3 with Barium Additions,” J. Am. Ceram. Soc., 70, c18-21 (1987).
4. 4 L. Egerton and D. M. Dilliom , “Piezoelectric and Dielectric Properties of Ceramics in the System Potassium-Sodium Niobate,” J. Am. Ceram. Soc., 42, 438-42 (1959).
5. 5 R. E. Jaeger and L. Egerton , “Hot Pressing of Potassium-Sodium Niobates,” J. Am. Ceram. Soc., 45, 209-13 (1962).