J. Miao et al., MAGNETIC LOCALIZATION OF FREE-EXCITON MAGNETIC POLARONS IN DILUTED MAGNETIC SEMICONDUCTORS, Journal of applied physics, 81(9), 1997, pp. 6297-6302
A model of free exciton magnetic polarons (EMPs) in diluted magnetic s
emiconductors is proposed on the basis of the localization of the hole
in the magnetic potential well created by its own exchange field. The
corresponding calculations of the free EMP binding energies, as a fun
ction of Mn2+ ion concentration and temperature, are performed. The re
sults are in good agreement with recent experimental measurements. It
is found that free EMPs are stable up to relatively high temperatures
(T less than or similar to 30 K) over a wide range of Mn concentration
s x without any other primary localization, e.g., alloy potential fluc
tuations. The dependence of the critical temperature of free EMP forma
tion on the Mn concentration is determined for various diluted magneti
c semiconductor materials, and is in good agreement with the experimen
tal results for Cd1-xMnxTe. The suppression of free EMPs under the app
lication of an external magnetic field is also considered. (C) 1997 Am
erican Institute of Physics.