Novel approach to description of optical and magnetotransport data in dilute magnetic semiconductors near semimetal-semiconductor transition

The peculiarities of the exchange interaction between the carrier spin and localized spin moments of magnetic ions near the semimetal-semiconductor tr ansition have been studied in semimagnetic quaternary solid solution system s, Hg1-x-yCdxMnySe and Hg1-x-yCdxMnyTe by means of Shubnikov-de Haas oscill ations and photolumincscence. The measurements show that the exchange const ant alpha is actually a somewhat complicated function of energy gap and ele ctron concentration. The exchange interaction is responsible for the spin-R ip transitions observed both in the PL and magnetoresistance measurements i n narrow-gap Hg1-x-yCdxMnyTe. (C) 2000 Published by Elsevier Science B.V. A ll rights reserved.