Effect of growth temperature on the structural and magnetic properties of the pulsed laser deposited Co2FeAl thin films

Abstract

A set of Co2FeAl (CFA) Heusler alloy thin films have been prepared at different substrate temperatures using the Pulsed Laser Deposition (PLD) technique and the effect of growth temperature on the structural and magnetic properties of the films have been studied in detail. Preliminary structural characterization of the films have been carried out by Grazing Incidence X-ray diffraction (GIXRD) measurements, while the thickness and roughness of the films have been estimated by Grazing incidence X-ray reflectivity (GIXR) measurements. The element specific X-ray absorption spectroscopy (XAS) technique comprising of both Extended X-ray absorption fine structure (EXAFS) and X-ray near edge structure (XANES) measurements have been carried out on the samples both at Fe and Co K edges and the results have been analysed to quantitatively determine the various bond lengths around both Fe and Co sites which ultimately gives information regarding relative strength of d-d hybridization over p-d hybridization in the samples. Finally the magnetic behavior of the samples have been measured thoroughly as a function of temperature and magnetic field and variation of the magnetization of the samples on the crystallite size and substrate temperature has been studied. The nature of the spin wave in the thermal demagnetization of spontaneous magnetization has also been explored. The structural information obtained from EXAFS measurements have been correlated with the magnetic properties of the samples.