Abstract
Wurtzite GaN on (0001) sapphire is studied by mean of reflectance and magnetocircular dichroism up to 5.5 T at 2 K. This very powerful technique allows us to determine the Zeeman splittings, for the first time to our knowledge, to be about 0.05 meV/T for the X-A and X-C excitons and almost zero for the X-B exciton. (C) 1997 Elsevier Science S.A.