Method of making a transparent ferroelectric ceramic element
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsSyunichiro Kawashima, Masamitsu Nishida, Yoshihiro Matsuo, Hiromu Ouchi, Shigeru Hayakawa
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Abstract
A method of making an electrooptical system including a transparent ferroelectric ceramic element which possesses memory in that a birefringence corresponding to an applied electric field remains after the field is removed. The electrooptical element is hot-pressed from a family of materials which comprises solid solution of the ternary system, lead magnesium niobate-lead titanate-lead zirconate, and the hot-pressed material may additionally contain a small amount of lanthanum oxide (La.sub.2 O.sub.3).
Claims3
A method of making a transparent ferroelectric ceramic element, comprising the steps of:
- forming a solid solution of a material of the formula
- Pb.sub.1-(3/2)t La.sub.t (Mg.sub.160 Nb.sub.2/3).sub.x Zr.sub.y Ti.sub.z O.sub.e +.alpha.PbO,
- where t=0.04-0.15, x=0.03-0.60, y=0.10-0.95, z=0.05-0.90, x+y+z=1, and .alpha.=0.00 -0.20;
- grinding said solid solution to form a ferroelectric powder;
- and
- hot-pressing said powder at a temperature between 900.degree. C and 1300.degree. C and at a pressure of at least 1000 p.s.i. for a period of time which is sufficient to form a transparent ferroelectric ceramic element.
Dependencies are inferred from the claim text.