Download (4Mb) - Etheses - Saurashtra University

Chapter II Solution Growth….
(1) Low Temperature Solution Growth
This technique is used for materials having very good solubility at room
temperature in water or any other solvents. In the aqueous solution growth
technique, water is used as a solvent; while in non-aqueous techniques other
than water is used as a solvent. This method hinges on achieving super-
saturation without inducing spontaneous nucleation, so that the growth can
proceed on the seed material. Super-saturation can be achieved and
maintained in a number of ways, depending upon the conditions of the
experiment and desired results. Broadly speaking, in the solution growth, the
solvent can be evaporated (slow evaporation technique), the solution
temperature can be decreased (slow cooling technique) or solution, saturated
at a temperature higher than the growth temperature, can be continuously
added into the growth vessel (temperature differential method). Many ionic
salt crystals as well as organic material crystals have been grown for different
applications. Large size KDP (Potassium Dihydrogen Phosphate) single
crystals have been grown for LASER applications. The dimensions of KDP
crystals are 26 x 21 x 23 inches, and weighing 700 lbs [36].
(2) High Temperature Solution Growth
This technique is also known as flux growth. Molten salts are the only
solvents for oxides or solid solutions of oxides, which are having very high
melting points and/or decompose before melting. Oxides or fluorides are
dissolved in a flux and the growth proceeds at relatively low temperatures,
often as much as 1000 0 C below the melting point of the solute. The common
68