FARADAY-ROTATION OF FERROMAGNETIC (GA, MN)AS

Faraday rotation of (Ga, Mn)As, with an Mn composition of 0.043, is pr esented. The measurements were performed in the Fundamental aborption edge region (1.24-1.8eV) at 10K (ferromagnetic phase) and at room temp erature (paramagnetic phase). The magnetic behaviour of(Gal Mn)As mani fests itself in the magnetic field dependence of Faraday rotation, whi ch was found to be proportional to the magnetisation of the sample. A large Faraday rotation of 6 x 10(4) deg/cm (at 0.1 T, 1.55eV) at 10K i s observed. The Verdet constant at room temperature is 8 x 10(-2) deg/ G.cm (1.49eV).