Ferromagnetism In Sol-gel Derived ZnO: Mn Nanocrystalline Thin Films

Abstract

This paper reports the growth of Mn doped ZnO thin films by sol-gel technique with different Mn concentration (0-20 %). Structural and vibrational properties have been measured by X-ray diffraction and Raman spectroscopy. The films exhibit crystalline nature with (002) preferential orientation. The crystallite size and lattice parameters have been estimated as a function of Mn concentration. The Raman spectrum of the ZnO film shows the peaks corresponding to E2 (high) mode at 434 cm -1 assigned to Zn-O bond and A1 (LO) mode at 575 cm -1 . The elemental analysis of the films have been performed using X-ray photoelectron spectroscopy confirms the presence of Zn, O and Mn in doped films. Surface morphology and roughness of the films are observed by atomic force microscopy. The optical bandgap is found to decrease with Mn concentration as estimated by Tauc's plots. Room temperature ferromagnetism has been obtained in ZnO: Mn thin films by superconducting quantum interference device.