Study of magnetic properties of cobalt based thin film alloys

Abstract

newline Solids exhibit anomalous physical and chemical properties at reduced newlinedimensions. Thin film materials become ideal systems for studying two dimensional newlinesystem. In general thin films need to be supported by substrate materials. The interface newlinebetween the thin film and substrate exhibits properties that are different from that of thin newlinefilm and substrate material. Substrates strongly influence the properties of thin films. newlineThe parameters such as electron correlation effects and spin orbit coupling are known to newlineinfluence the electric and magnetic properties of 3d transition metals and alloys in the newlinebulk form. There is few systematic study available to understand how these parameters newlinemanifest in low dimensional systems. Thin layers of Cobalt (Co) and its alloys with other newline3d transition metals such as Ti, Fe and Ni play an important role both in fundamental and newlinetechnological point of view. These alloys find applications in spintronic based devices newlinesuch as hard disk drive heads and magnetic RAM. The ground states of some of the newlinealloys seem to depend on the composition. newlineCo1-xNix (x = 0.2, 0.4, and 0.6), Co1-xFex (x = 0.8, 0.7, and 0.6) and Co1-xTix (x = newline newline0.3, 0.5, and 0.7) thin film alloys were prepared on clean Si(100) substrate using dc- newlinemagnetron sputtering technique. The prepared thin films alloys were characterized using newline newlineGIXRD, XRR, EDAX, AFM and XPS techniques. Magnetic properties of the alloys newlinewere investigated using Magneto Optic Kerr Microscopy. It was observed that the newlineproperty of the Co alloys strongly depends on the alloying element such as Ni, Ti or Fe. newlineHere, EDAX and XPS measurements indicate that prepared thin film alloys have no newlineimpurities. newlineThe structural analysis of Co-Ni thin film alloys suggests a phase transition has newlineoccurred from hcp to fcc crystal structure with composition. The obtained thickness of newlineCo-Ni thin film alloys is about 30 nm. The dependence of magnetic properties such as newlinemagnetic anisotropy and anisotropy dispersion on Co concentration was observed in newlinethese alloys. Angular dependence of remanent magnetization shows that these alloys newlineexhibit strong uniaxial anisotropy and it decreases with increase of cobalt concentration