| 摘要 |
In a method of growing a crystal of quartz on a seed crystal by a hydrothermal technique, the rate of deposition of quartz on the seed crystal is controlled so that the growth rate does not exceed 0,275 mms. per day on each growth face. The seed crystal may take the form of a thin plate cut with its least dimension lying in the direction of the optic axis, and the source material from which the crystal is grown is preferably crushed quartz of high purity. Deposition of quartz on the seed crystal may be effected in the presence of sodium carbonate solution with or without sodium hydroxide at a temperature of 330 DEG -400 DEG C. Examples are given. Specification 811,215 is referred to. |
