| 摘要 |
PURPOSE:When a single crystal of lithium niobate is made single domain, a pair of electrodes are set on both sides of the single crystal along the Z-axis, they are heated at a specific temperature, then the single crystal is made single domain at a temperature lower than the above one, thus preventing the crack formation in the later dicing and cutting processes. CONSTITUTION:Lithium carbonate and diniobium trioxide, as raw materials of lithium niobate, are melted in a platinum crucible and a seed crystal of lithium niobate is dipped in the melt. Then, the seed crystal is gradually pulled up to effect the growth of the single crystal. A pair of electrodes are set on both sides of the single crystal along the Z-axis and the crystal is kept at a constant temperature ranging from 1,180 to 1,230 deg.C in an electric furnace for 5hr. Then, it is gradually cooled down to 1,145-1,160 deg.C and a voltage of 2V/cm is applied to both electrodes at the same temperature for one hour. Further the crystal is cooled down at a rate of 100 deg.C/hr and the application of the voltage is stopped, when the temperature becomes lower than 100 deg.C, whereby the crystal is made single domain. |
