Pulsed laser deposition and characterization of Zn1-xMnxO films

Here we present our results of structural, optical, and magnetic measurements of Zn1-xMnxO thin films. These films were grown epitaxially on (0001) sapphire substrates by using pulsed laser deposition technique. The maximum Mn content (x=0.36) is found to be much higher than allowed by thermal equlibrium limit (x~0.13) due to the non-equilibrium nature of the pulsed laser deposition. All the films investigated here were found to be single phase with <0001> orientation epitaxial relationship. A linear increase in the c-axis lattice constant was observed with increase in Mn concentration. Optical transmittance measurements showed an increase in the insulating band-gap (Eg) with increase in Mn concentration. DC magnetization measurements showed that there is no long range ferromagnetic ordering down to 10 K.