Flux method is a method of crystal growth where the components of the desired substance are dissolved in a solvent (flux). The method is particularly suitable for crystals needing to be free from thermal strain. It takes place in a crucible made of highly stable, non-reactive material. For production of oxide crystals, metals such as platinum, tantalum, and niobium are common. Production of metallic crystals generally uses crucibles made from ceramics such as alumina, zirconia, and boron nitride. The crucibles and their contents are often isolated from the air for reaction, either by sealing them in a quartz ampoule or by using a furnace with atmosphere control. A saturated solution is prepared by keeping the constituents of the desired crystal and the flux at a temperature slightly above