Browsing by Author "Suzuki, K"

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    Exchange-stiffness constant of a Nd-Fe-B based nanocomposite determined by magnetic neutron scattering
    (American Institute of Physics, 2013-09-16) Bick, JP; Suzuki, K; Gilbert, EP; Forgan, EM; Schweins, R; Lindner, P; Kubel, C; Michels, A
    We report magnetic-field-dependent small-angle neutron scattering (SANS) experiments on a Nd2Fe14B/Fe3B nanocomposite. For the two scattering geometries where the applied magnetic field is either perpendicular or parallel to the incoming neutron beam, we have independently analyzed the field-dependent SANS data in terms of micromagnetic theory, taking into account demagnetizing-field effects. The approach in reciprocal space is supported by an analysis of the data in real space and provides consistent results for the exchange-stiffness parameter and the mean magnetic anisotropy-field radius. © 2013, American Institute of Physics.
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    Magnetization reversal in Nd-Fe-B based nanocomposites as seen by magnetic small-angle neutron scattering
    (American Institute of Physics, 2013-01-14) Bick, JP; Honecker, D; Dobrich, F; Suzuki, K; Gilbert, EP; Frielinghaus, H; Kohlbrecher, J; Gavilano, J; Forgan, EM; Schweins, R; Lindner, P; Birringer, R; Michels, A
    We have studied the magnetization-reversal process of a Nd2Fe14B/Fe3B nanocomposite using small-angle neutron scattering. Based on the computation of the autocorrelation function of the spin misalignment, we have estimated the characteristic size l(C) of spin inhomogeneities around the Nd2Fe14B nanoparticles. The quantity l(C) approaches a constant value of about 12.5 nm (similar to average Nd2Fe14B particle radius) at 14 T and takes on a maximum value of about 18.5 nm at the coercive field of -0.55 T. The field dependence of l(C) can be described by a model that takes into account the convolution relationship between the nuclear and the magnetic microstructure. © 2013, American Institute of Physics
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    Microstructure of Cr (N,O) thin films studied by high resolution transmission electron microscopy
    (Elsevier, 2017-03-01) Suzuki, K; Suematsu, H; Thorogood, GJ; Suzuki, T
    In order to obtain insight into the hardening mechanism of Cr(N,O) thin films with respect to increase in oxygen content, the microstructure of Cr(N,O) grains in thin films was studied. High resolution transmission electron microscopy provided evidence that the grains in Cr(N,O) thin films prepared by pulsed laser deposition, which have an oxygen content of > 27 mol%, contained stacking faults. Phase identification via electron diffraction, indicated that the grains consisted of two phases, which had a NaCl-type and corundum-type structure and these phases had the same orientation as that of the Cr0.67O thin film. The estimated stacking fault energy of Cr(N,O) with an oxygen content of 34 mol% was 20 mJ/m2. Our results revealed the Cr(N,O) grains had the same nano-lamellar morphology as that of the Cr0.67O thin film which supports the possibility that the nano-lamellar morphology was formed by the introduction of extended dislocations. It is also possible that the hardening of Cr(N,O) was caused by dislocation pinning at the boundaries of the nano-lamellar morphology. © 2017 Elsevier B.V