The homogeneity of CdP2, ZnP2, and ZnGeP2 crystals doped with Mn, Fe,
and Co was characterized by optical transmission, Hall effect, and dis
location density measurements. The dopant content of the crystals was
determined by secondary-ion mass spectrometry. Doping with phosphides
instead of pure metals was found to ensure a more uniform dopant distr
ibution and a marked decrease in dislocation density.