Hydrothermal growth of zinc oxide crystals

摘要

Zinc oxide crystals are grown from a solution by immersing a seed crystal of ZnO and a mass of nutrient ZnO in an aqueous medium containing lithium ions and the hydroxide of another alkali metal, or the hydroxide of an PICT:1061831/C1/1 alkaline earth metal, or a mixture of said hydroxides, the lithium ion and the metal hydroxide having concentrations of 0.1 to 4.0 molal and 2 to 8 molal respectively, and heating said aqueous medium to a temperature of at least 300 DEG C. at a pressure of at least 3200 p.s.i. while maintaining the temperature of the nutrient mass from 5 DEG to 100 DEG C. above that of the growth region. The apparatus used may be a pressure-temperature bomb with casing 10 sealed by cover 11 and plunger 12. Disc 14 and plunger 12 seal liner 13, which is of a noble metal, say Ag, as is lip 15. Growth seed 16 is suspended by Ag wire 19 and separated by baffle 18 from nutrient mass 17 of nutrient ZnO particles. Solution 20 contains lithium ions and the hydroxides, specified sources being CH3CO2Li, Li2B4O7, lithium citrate, HCO2Li, LiOH, LiNO3, (CO2)2Li2, Li2SO4 and lithium halides and NaOH, KOM, CsOH, RbOH, Sr(OH)2 and Ba(OH)2 respectively,