Commercially available gases contain residual impurities leading to a background oxygen partial pressure of typically several 10^{ -6} bar, independent of temperature. This oxygen partial pressure is inappropriate for the growth of some single crystals where the desired oxidation state possesses a narrow stability field. Equilibrium thermodynamic calculations allow the determination of dynamic atmosphere compositions yielding such self adjusting and temperature dependent oxygen partial pressures, that crystals like ZnO, Ga2O3, or Fe{ 1-x}O can be grown from the melt.
Categories: cond-mat.mtrl-sci physics.chem-ph