Increasing Mn substitution in magnetic semiconductors through controlled ambient annealing processes

We report on a controlled ambient annealing technique aimed at increasing the amount of Mn incorporation in III–V semiconductors. The aim is to reduce the number of hole carrier and magnetic element compensating entities, such as Mn interstitials and anti-site defects, to increase the magnetic Curie temperature. The idea is (a) to increase the number of Group III vacancies through annealing in Group V vapor rich conditions and (b) judicious use of crystal field theory to reduce/stabilize Mn interstitials. Our experimental results constitute the highest reported Tc (∼130 K) in Mn doped InSb and Mn doped InP. The possibility of ferrimagnetism in Mn and Cr incorporated GaAs, was noted.