Investigation of Fe/Al multilayers (original) (raw)
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Investigation of magnetic properties in 57 Fe/Al multilayers
ICAME 2007, 2009
Fe/Al multilayer thin films prepared by ion beam sputtering, with an overall atomic concentration ratio of Fe/Al = 1:2 have been studied by x-ray diffraction spectroscopy (XRD), X-ray reflectivity (XRR) and D.C. Magnetization. These studies show the formation of Fe-Al intermetallic layers. Two magnetic regions and transition temperatures of 473 and 533 K are evident from magnetization studies. Conversion Electron Mössbauer Spectroscopy (CEMS) shows formation of off-stoichiometric Fe 3 Al like phase and phases consisting of pure Fe and Fe-rich extended Fe-Al solutions.
Magnetic and structural properties of Fe/Al multilayers
Journal of Magnetism and Magnetic Materials, 2002
Static and dynamic magnetic properties of Fe/Al multilayers, grown by RF magnetron sputtering on Si(1 0 0), are investigated. Magneto-Optical Kerr Effect shows in-plane uniaxial anisotropy and very soft behavior on six samples characterized by different number of bilayers. The coercive fields range between 2 and 8 Oe. Brillouin light scattering reveals spin-wave surface modes that depend on the number of Fe/Al repetitions and are attributed to the total multilayer stack and to individual layers. r
Size-dependent magnetic properties in Fe/Al multilayers
Journal of Magnetism and Magnetic Materials, 2000
Morphological and magnetic properties of Fe/Al ultra-thin "lm multilayers are studied as a function of Fe layer thickness by means of transmission electron microscopy, conversion electron MoK ssbauer spectroscopy, alternating gradient force magnetometry and AC susceptometry. With decreasing iron layer thickness, aluminum di!usion causes a progressive loss of periodicity and the formation of particulate systems. The magnetic behavior progressively evolves from ferromagnetic to superparamagnetic.
Ferromagnetic resonance study of Fe rich Fe–Al intermetallic alloys
Journal of Magnetism and Magnetic Materials, 2007
With the aim of studying the evolution of the magnetic clusters present in Fe-Al alloys around 30 at% Al with temperature we have used ferromagnetic resonance (FMR). FMR is a very powerful technique for magnetic characterisation of materials. In multiphase magnetic materials, FMR provides information about the magnetic exchange coupling that may exist between the various magnetic phases. In the present work we report study of 4 alloys with compositions Fe 69:5 Al 30:5 , Fe 70 Al 30 , Fe 70:5 Al 29:5 and Fe 72:5 Al 27:5. The resonance field shows strong temperature dependence. Despite the small composition variations between the studied samples, the resonance field temperature dependence varies significantly. This indicates that the magnetic cluster structure is strongly dependent on composition. Moreover, the FMR field shows magnetic transition temperatures already reported by other techniques.
Effect of Al overlayers on the magnetic properties of Fe thin films
In this work, we report on the e!ect of Al overlayers on the magnetic properties of Fe thin "lms. In-plane ferromagnetic resonance has been used to measure the resonance "eld and linewidth, as a function of the azimuthal angle, H, and Al layer thickness, t . The data are interpreted in the framework of a model that includes cubic magnetocrystalline and out-of-plane uniaxial anisotropies, and dispersions of the cubic axes. The main e!ect of the Al overlayer is to enhance the cubic magnetocrystalline anisotropy of the Fe "lm and to reduce the out-of-plane uniaxial anisotropy. The Al layer also induces angular dispersion in the cubic axes. We found no clear evidence of a 1/ t dependence of the sample parameters, as expected for interface e!ects.
Two magnetic-ordering temperatures in Fe/Al multilayered films
Physical Review B, 1992
We have prepared Fe/Al multilayers with individual layer thickness ranging from 5 to 200 A. For magnetic measurements, each sample was cooled in zero magnetic field from room temperature to 5 K. Then a magnetic field of 100 G was applied, and the magnetization was measured as the temperature was raised from 5 to 300 K. The magnetization initially rose as the temperature increased to a certain temperature T~, beyond which the magnetization decreased with further increase in the temperature. The peak at T~w as found in all of our samples of different layer thicknesses. We have also measured the Curie temperature T& and found it considerably higher than T~. We show that T~r epresents a transition from one magnetic state to another, and it is suggested that it is probably due to an antiferromagnetic coupling between the Fe layers via the Al layers. &=so k &=30 k
Journal of Applied Physics, 2008
Fe/Al multilayer thin films with an overall atomic concentration ratio of Fe: Al=1:2 have been prepared by ion-beam sputtering. Phase formation and microstructural evolution with thermal annealing have been studied by x-ray reflectivity, cross-sectional transmission electron microscopy, dc magnetization, and conversion electron Mössbauer spectroscopy. These studies show that although the starting composition is Al rich, the intermixing of Fe and Al at the interfaces leads to the formation of a magnetic Fe 3 Al-like region at the interface. Thus, the magnetic contribution in the as-deposited multilayer structure ͑MLS͒ is not only from pure Fe but also from an Fe 3 Al-like region formed at the interface. On annealing the MLS, a stable nonmagnetic MLS consisting of intermetallic B2 Fe 50 Al 50 separated by thin Al layers is formed. Further annealing only induces better ordering of Fe 50 Al 50 and does not destroy the MLS.
Study of interface structure of Fe/Al multilayers
Journal of Applied Physics, 1996
Structural and magnetic ordering of the interfaces determines the physical properties of multilayered structures. Interfaces of Fe/Al multilayers were studied using Mössbauer effect spectroscopy. The samples were fabricated by dc planar magnetron sputtering at room temperature on polyester substrates. The observed spectra indicate that the interfaces have a common structural composition and for thin Fe layers, the whole Fe layer forms mixed phases at the interface. For larger Fe layer thickness, the interface is formed using an about 12-Å-thick Fe layer. Besides the hyperfine field component of bcc Fe, six different magnetic components were identified in all samples ͑with larger Fe layer thickness͒. The intensities of the components were determined from the area under the absorption peaks of the Mössbauer spectra of the corresponding phases. The average canting angle of the Fe magnetic moments, as obtained from the spectra, indicate parallel magnetic anisotropy for all phases.
Fe/Al multilayered magnetoresistance at Low temperature to room temperature
isara solutions, 2017
By using electron beam gun and thermal deposition techniques in the vacuum range 6 x10-5mbar (V.R. Technology Bangalore Make). The pure materials of 99.99% purity of iron and aluminium multilayers films grown on glass substrates at 300K in the following viz. [FE10Å/AL10Å]N where N= 1,3,6,9 and 12 labeled as ( FA1, FA2, FA3, FA4 and FA5). The resistance was measured using four probe method at UGC-DAE Consortium Indore (4.2K to 300K) later magnetoresistance were calculated. it is first time this set of films have explore magnetoresistivity at low down temperature.
Journal of Applied …, 2008
Fe/Al multilayer thin films with an overall atomic concentration ratio of Fe: Al=1:2 have been prepared by ion-beam sputtering. Phase formation and microstructural evolution with thermal annealing have been studied by x-ray reflectivity, cross-sectional transmission electron microscopy, dc magnetization, and conversion electron Mössbauer spectroscopy. These studies show that although the starting composition is Al rich, the intermixing of Fe and Al at the interfaces leads to the formation of a magnetic Fe 3 Al-like region at the interface. Thus, the magnetic contribution in the as-deposited multilayer structure ͑MLS͒ is not only from pure Fe but also from an Fe 3 Al-like region formed at the interface. On annealing the MLS, a stable nonmagnetic MLS consisting of intermetallic B2 Fe 50 Al 50 separated by thin Al layers is formed. Further annealing only induces better ordering of Fe 50 Al 50 and does not destroy the MLS.