G S Case

Publications (6)1.42 Total impact

• Article: Magnetic Anisotropy Studies in Ce/Fe and U/Fe Multilayers

  M.F. Thomas, G.S. Case, J. Bland, C.A. Lucas, A. Herring, W.G. Stirling, P. Boni, S. Tixier, R.C.C. Ward, M.R. Wells, S. Langridge
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  ABSTRACT: Multilayer samples of Ce/Fe, fabricated by sputtering and characterized by X-ray diffraction and reflectivity were studied by polarized neutron reflectivity and Mössbauer spectroscopy. Corresponding studies on sputtered U/Fe multilayers have been initiated. In Fe/Ce a paramagnetic phase, identified as amorphous Fe was observed at Fe thicknesses below 20 Å. Perpendicular magnetic anisotropy was observed for Fe thicknesses below 17 Å and studies in applied fields enabled magnetic anisotropies to be evaluated for Fe thicknesses up to 40 Å. The Ce/Fe interface anisotropy was evaluated as Ks = (0.98 ± 0.15) × 10—3 Jm—2, among the largest values reported. Neutron reflectivity results did not observe magnetic moments on Ce layers. Preliminary measurements on U/Fe multilayers have not observed induced moments on the U layers.
  physica status solidi (a) 02/2002; 189(2):537 - 543. · 1.21 Impact Factor
• Article: Magnetic anisotropy in multilayers

  M.F. Thomas, J. Bland, G.S. Case, J.A. Hutchings, O. Nikolov
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  ABSTRACT: Magnetic anisotropy between in-plane and out of plane magnetic alignments is studied in a variety of multilayer systems using Mössbauer spectrosopy to observe the (Fe) magnetic orientation. The surface anisotropy in Fe/Au (1 1 1) multilayers is measured as K s = 0.9 × 10−3 Jm−2. In Fe/Ni multilayers the dependence of magnetic orientation on external field applied normal to the layers enables volume and interface anisotropies K v = (−5 ± 1) × 104 Jm−3 and K s = (−0.6 ± 0.4)× 10−3 Jm−2 to be evaluated. In similar applied field experiments coherent rotation of the magnetic Fe and NiFe layers in Fe/Cu/NiFe/Cu multilayers was observed for intervening Cu layer thickness x = 5 Å but independent rotation for x = 50 Å. Out of plane magnetic components are observed for DyFe2, YFe2 thin films and DyFe2/YFe2 multilayers. In fields of up to 0.25 T applied inplane only the moments of the YFe2 film showed significant rotation.
  Hyperfine Interactions 06/2000; 126(1):377-386. · 0.21 Impact Factor
• Article: Synthesis, powder neutron diffraction structures and Mossbauer studies of some complex iron oxyfluorides: Sr3Fe2O6F0.87, Sr2FeO3F and Ba2InFeO5F0.68

  G S Case, A L Hector, W Levason, R L Needs, M F Thomas, M T Weller
• Article: Structural and Mossbauer studies of Sr2FeO3 (X=F, Cl, Br) and the magnetic structure of Sr2FeO3F

  G S Case, A L Hector, R L Needs, M F Thomas, M T Weller
• Article: Studies on rare-earth/iron and actinide/iron multilayers

  M F Thomas, G S Case, J Bland, A D F Herring, W G Stirling, S Tixier, O Boni, R C C Ward, M R Wells, S Langridge
• Article: Magnetic anisotropy in Ce/Fe and Ce/FeCoV multilayers

  G S Case, M F Thomas, C A Lucas, D Mannix, P Boni, S Tixier, S Langridge