Search

We investigate the structural properties of Fe 1 − x Ni x /Cu/Fe 1 − x Ni x (x=0.5, non-Invar and x=0.36, Invar) trilayers deposited on Si(100) at room temperature using the dc magnetron sputtering technique in ultra high vacuum conditions taking high-purity Fe, Ni and Cu metals with Cu layer thickness 4, 6 and 8 nm for each alloy composition. The structure of the alloy films of the trilayers was investigated using x-ray diffraction and the thickness and roughness of the layers were obtained by x-ray reflectivity measurement. Both the as-prepared and annealed trilayers exhibit layered structure. The as-deposited Fe–Ni alloy in non-Invar trilayer exhibits only the fcc structure. whereas in the Invar alloy it exhibits a mixed fcc and bcc phases. Interestingly after annealing at 425 ∘ C in ultra high vacuum, the Invar alloy completely transformed to the fcc structure for all Cu thicknesses. In both Invar and non-Invar trilayers, the Bragg reflections corresponding to Fe–Ni alloy layers become sharp after annealing. The induced structural transformation in the Invar trilayer is explained using enhanced diffusion of Fe and Ni atoms at high temperatures. [ABSTRACT FROM AUTHOR]

Co1–xTix (x = 0.3, 0.5 and 0.7) thin films were prepared on Si (100) substrate using DC-magnetron sputtering deposition technique. A structural phase transition occurs from hexagonal to cubic crystal structure when the Ti composition is above 30 percentage. The thickness of the films obtained from X-ray Reflectivity data is about 30 nm. The average particle size of the CoTi thin films was calculated using the Atomic Force Microscopy image. The Magneto-Optic Kerr Effect measurements suggest that only Co0.7Ti0.3 thin film exhibits soft magnetic behaviour whereas the other thin films have no magnetic properties because of small grain size and reduction of inter-grain exchange interaction. Co0.7Ti0.3 thin film has twofold magnetic anisotropy. The angle-dependent coercivity (Hc) is numerically fitted with a two-phase model of magnetization reversal, which confirms the presence of magnetic anisotropy. The magnetization reversal occurs via coherent rotation of spins along the hard axis. [ABSTRACT FROM AUTHOR]

Cobalt-iron thin film was deposited on rotating silicon (100) substrate using the DC-magnetron sputtering deposition unit. The structure is examined by Grazing Incidence X-ray Diffraction and results reveal that the sample has a bcc crystal structure with lattice constant 2.65 Å. The X-ray Reflectivity data analysis confirms that the thickness of the thin film alloy is about 33 nm. The Energy Dispersive X-ray Analysis confirms the presence of 30.56% of cobalt and 69.44% of iron in cobalt-iron thin film. The study of magnetic properties by Magneto-Optic Kerr Effect technique suggests that sample exhibits soft magnetic behavior. The M–H loop study shows that the coercive field decreases with the increase of rotation of the substrate which may be due to reduced grain size or crystal orientation. The study of remanence magnetization (Mr/Ms) confirms that the sample has a twofold magnetic structure and cubic magnetic anisotropy. The occurrence of the magnetization reversal in the sample is due to the formation of the ripples and change in the contrast in the color of domain images along the easy axis and through coherent rotation of spins along the hard axis. This confirms that the sample has uniaxial nature and found very useful applications in the magnetic sensors, memory storage devices and spintronics. [ABSTRACT FROM AUTHOR]