Bake out
Bakeout refers to the removal of undesirable and sometimes harmful influences, such as adsorbed substances on surfaces (e.g. water), impurities or constellations (e.g. crystal lattice defects) from materials or devices by means of controlled heating to a certain temperature above defined Spans of time.
In some cases, additional measures are necessary so that the removed substances do not immediately contaminate the materials to be cleaned again. For example, desorbed residual gases are sucked off with the aid of vacuum pumps . That is, the samples are baked out under vacuum.
Applications
Baking is used almost everywhere in material processing and coating. Especially in the high vacuum technology , in material deposits in semiconductor technology, for example to resolve by ion implantation resulting crystal damage (so-called "healing", English annealing ). The same applies to stress relief annealing in metalworking.
Further applications are the controlled removal of Wigner energy in graphite-moderated nuclear reactors or sterilization by heating in medicine.
In order to keep the evacuation times of electron tubes short, the inner metal parts are brought to glow in a targeted manner in a high-frequency field similar to that in a microwave oven.
In the chemical laboratory, glass apparatuses are baked out - usually with simultaneous evacuation - in order to condition them before carrying out certain sensitive analyzes or syntheses.