| 摘要 |
1515314 Polarizing ferro-electric substances COMMISSARIAT A L'ENERGIE ATOMIQUE 21 May 1975 [30 May 1974] 21761/75 Heading H1E A method of polarizing a ferro-electric material which exhibits a Curie point at a temperature T c , without applying an external electric field thereto, comprises bringing a solid body of the material to a temperature above the Curie point T c , but below the fusion-temperature of the material, establishing and maintaining a longitudinal temperature gradient along a linear dimension of the body without bringing any part of the body to the fusion-temperature, suppressing the temperature-gradient by equalizing the temperature of the heated material, as a preparation for, and prior to, transition back through the Curie point T c , and finally bringing the material back through the temperature T c . The preferred material is a crystal of Lithium Niobate having a thickness of 1 cm. along the ferro-electric axis C. It is heated to 15‹ C. above the Curie point (1150‹ C.). A thermal gradient of 10‹ C./cm. is then applied along axis C for one hour. The thermal gradient is then suppressed and the temperature allowed to decrease, slowly, at the rate of 300‹ C./hour. |
