| 摘要 |
PURPOSE:To reduce extremely the crack of a single crystal caused by single domain formation, by heating the single crystal of lithium tantalate at a given temperature, applying moderately a fixed electric field to it so that the single crystal is subjected to single domain formation. CONSTITUTION:The pulled lithium tantalate single crystal 3 is set in the electric furnace 2, and heated to a fixed temperature such as 650 deg.C by the heater 1. The switch 7 is turned on, the voltage is raised to the desired voltage such as 60V, and the crystal is treated for about 20min. In the operation, the application of electric field, for example, is carried out moderately at a rate of 10V/min. The temperature is lowered at a rate of about 200 deg.C/hr. Consequently, cracks will hardly occur in the single crystal. |
