| Abstract: | The effect of film thickness and substrate orientation on ferromagnetism in Mn doped ZnO thin films have been studied. The Mn doped ZnO films of different thickness (15, 35 and 105 nm) have been grown on both Si (100) and Si (111) substrates. The structural, electrical, optical, elemental and magnetic properties of the films have been investigated by X‐ray diffraction (XRD), Hall Effect measurements, photoluminescence (PL), energy dispersive spectroscopy (EDS) and vibrating sample magnetometer (VSM), respectively. It is found that all the properties are strongly influenced by the film thickness and substrate orientation. The XRD analysis confirmed that the formation of high quality monophasic hexagonal wurtzite structure for all the grown films. The room temperature VSM measurements showed that the films of lower thickness have better ferromagnetism than that of the thicker films grown on both the substrates. Among the lower thickness films, the film grown on Si (111) substrate has higher saturation magnetization (291×10‐5 emu cm‐3) due to high density of the defects. The observed ferromagnetism has been well justified by XRD, Hall measurements and PL. The presence of Mn atoms in the film has been confirmed by EDS. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) |
