STUDY OF THE MOTT TRANSITION IN n-TYPE CdS BY SPIN FLIP RAMAN SCATTERING AND SPIN FARADAY ROTATION

Abstract

At a concentration of 2.4 × 1017 donors n-type CdS undergoes a metal-insulator transition. The diffusional character of the donor electrons is studied in the metallic regime by observing the collisionally narrowed Doppler linewidth of the spin-flip Raman scattering. The spin Faraday rotation of the donor electrons is used to measure the susceptibility of the electrons which shows in the transition region on the metallic side both temperature dependent and temperature independent components. We interpret our results in terms of a single phase strongly correlated electron gas, rather than as a two phase system