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US 4,027,074 AGranted
Process for producing ferroelectric crystalline material
AssigneeLeco Corporation
InventorsLeslie E. Cross, Raymond J. Kunz, Robert E. Newnham
Life of this patent
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Abstract
Lead germanate, Pb.sub.5 Ge.sub.3 O.sub.11, or lead germanate/silicate in which up to 2/3 on a molar basis of the germanium has been substituted with silicon, can be formed from a glassy state to a ferroelectric state by a simple annealing process. The lead germanate or lead germanate/silicate is heated to a temperature sufficient to anneal it into a crystalline phase, then cooled below the ferroelectric transition temperature for the composition while an electric field is applied.
Claims6
A process for producing a ferroelectric crystalline element, comprising the steps of:
- (1) forming a mass having the formula Pb.sub.5 Ge.sub.(3.sub.-x) Si.sub.x O.sub.11, wherein x ranges from 0-2, in a glassy state;
- (2) heating said mass to a temperature between about 450.degree. C. and the glass transition temperature of the composition to anneal the glassy mass into a crystalline mass;
- and
- (3) cooling the annealed mass while applying an electric field of about 15 to about 30 kilovolts/centimeter to a temperature below the ferroelectric transition temperature of the composition, to form a ferroelectric crystalline mass.
1 more element
Dependencies are inferred from the claim text.