In Zn1-xMnxSe, Mn2+ d-->d transitions were found to induce giant Fara
day rotation, and peaks of the Faraday rotation spectra were red-shift
ed Linearly with increasing Mn composition. Through studying the magne
to-optical transition variation with Mn composition, the Mn compositio
n can be determined. Results from the Faraday rotation analysis were c
ompared with the x-ray diffraction data and were found in good agreeme
nt with each other. (C) 1996 American Institute of Physics.