The non-stoichiometric cycles with a perovskite ABO can be describes with the following reactions:
::Reduction reaction: ABO → ABO + δ/2 O
::Oxidation reaction: ABO + δ HO → ABO + δ H
The reduction thermodynamics of perovskite makes it more favorable during the reduction half-cycle, during which more oxygen is produced; however, the oxidation thermodynamics proves less suitable, and sometimes perovskite is not completely oxidized. The two atomic sites, A and B, offer more doping possibilities and a much larger potential for different configurations.