Solid solubilities of magnetic ions in diluted magnetic semiconductors grown under equilibrium conditions

Abstract

We have investigated the general trend of solid solubility (SS) of magnetic ions in diluted-magnetic-semiconductor (DMS) materials. The SS's of Fe and Co in CdSe are found to be 0.24 and 0.11, respectively. We have also observed that the SS of magnetic ions in some systems of DMS materials shows a linear relationship to the product of the electronegativity ratio of magnetic ions to host cations and the ratio of the magnetic ion-anion bond length to the host cation-anion bond length. From this observation, it is argued that the SS of magnetic ions can always be expressed by a single stress parameter defined as \ensuremath{\Upsilon}=(\ensuremath{\Delta}X+1)(\ensuremath{\Delta}d+1) in ${\mathrm{Zn}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathit{M}}_{\mathit{x}}$Se and ${\mathrm{Cd}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathit{M}}_{\mathit{x}}$Se (M=Mn, Fe, and Co) crystals. And the critical stress that the natural crystal structure of the host semiconductor must sustain is observed to be strongly related to the relative size of the anion to the cation in ${\mathrm{Zn}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Mn}}_{\mathit{x}}$B (B=S, Se, and Te) DMS material systems.