Structural, optical and magnetic properties of diluted magnetic semiconducting Zn1-xMnxO films

We have investigated the structural, optical and magnetic properties of high quality epitaxial Zn1-xMnxO (diluted magnetic semiconductor) films. These films were deposited on (0001) sapphire substrate by a pulsed laser deposition technique. The nonequilibrium nature of the laser-material interaction allowed us to dope higher Mn contents (x = 0.36) than allowed by thermal equilibrium limit (x similar to 0.13). All the films investigated here were found to be single phased and epitaxial with (0001) orientation. As the Mn concentration increases in the system, the c-axis lattice constant was found to increase linearly. Optical transmittance study showed an increase in the insulating band-gap (E-g) with increase in Mn atomic fraction x following E-g = 3.270 + 2.760x - 4.988x eV. DC magnetization measurements showed the paramagnetic nature of the system. (C) 2002 Elsevier Science Ltd. All rights reserved.