| 摘要 |
1,219,983. Piezoelectric ceramics. MATSUSHITA ELECTRIC INDUSTRIAL CO. Ltd. 14 March, 1968 [14 March, 1967; 23 March, 1967], No. 12461/68. Heading C1J. A semi-conductive piezoelectric ceramic has the formula x + y + z = 1 and has a resistivity not greater than 7 x 10<SP>8</SP> ohm./cm. NiO 0�3 to 1% b.w. can be present. The ceramic is obtained by heating an appropriate mixture of the oxides at 1100- 1300� C. for at least 10 mins in an O 2 deficient atmosphere exemplified by N 2 , Ar, H 2 and their mixtures. Prefiring at 850� C. can be included. Reference has been directed by the Comptroller to Specification 1,066,752. |
