Electron Paramagnetic Resonance in Hg<sub>1-x</sub>Mn<sub>x</sub>Te<sub>1-y</sub>Se<sub>y</sub>

Abstract

Electron paramagnetic resonance has been studied in diluted magnetic semiconductor Hg 1-x Mn x Te 1-y Se y with y=0.01 and x=0.01, 0.03, 0.05, 0.14 and with y=0.075, x=0.14 in the temperature range 20-290 K. It is found that the EPR linewidth increases with increasing manganese concentration, and decreases with increasing selenium content. From the high temperature linewidth dependence the paramagnetic Curie-Weiss temperature is estimated as |θ |=10 K for the sample with x=0.01, y=0.01 and |θ |=18 K for x=0.03, y=0.01. These values of 6 together with those obtained in the magnetic susceptibility measurements give the nearest-neighbour exchange constant in Hg 1-x Mn x Te 1-y Se y with y=0.01, J NN /k B =-5.4 K. The calculated infinite temperature linewidths are considerably smaller than the extrapolated experimental values. We ascribe this effect to a coalescence of the Mn 2+ ion six hyperfine lines into a single broad peak.