Browsing by Author "Wolfson, EJ"

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    The effect of non-magnetic dilution of the Tb sublattice in TbCo3B2
    (Institute of Physics, 2010-01-20) Wolfson, EJ; Caspi, EN; Ettedgui, H; Shaked, H; Avdeev, M
    Solid solutions of Tb1-xYxCo3B2 (x = 0.05, 0.1, 0.25, 0.4 and 0.5) were studied by neutron powder diffraction, x-ray diffraction, AC susceptibility and SQUID magnetization measurements. Their magnetic and crystallographic properties were deduced and examined together with those previously published for the end compounds (x = 0, 1). These solid solutions have hexagonal symmetry and are paramagnetic at RT, and undergo a magnetic ordering transition of the Co sublattice, with the magnetic moments along the hexagonal axis, at T-Co similar to 150(15) K, independent of Y concentration. A second magnetic ordering transition of the Tb sublattice T-Tb <= 30 K accompanied by the rotation of the magnetic moments towards the basal plane, was observed for solid solutions with Y concentration x <= 0.25. This transition was also found to be accompanied by a crystallographic symmetry decrease. Unexpectedly, neutron powder diffraction showed that the magnitude of the ordered magnetic moment of the Tb ion decreases with Tb concentration. © 2010, Institute of Physics
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    Magnetic and crystallographic study of Tb0.75Y0.25Co3B2
    (Elsevier, 2008-03-02) Wolfson, EJ; Caspi, EN; Ettedgui, H; Shaked, H; Avdeev, M
    Tb0.75Y0.25Co3B2 was studied as a function of temperature by neutron powder diffraction, ac susceptibility and SQUID magnetization measurements. The solid solution, which is of hexagonal symmetry and is paramagnetic at 300 K, undergoes a magnetic Co-Co ordering transition at similar to 150 K, and a second magnetic Tb-Tb ordering transition at similar to 17 K. The latter induces a spin-reorientation transition, in which the magnetic axis rotates from the c-axis toward the basal plane. The component of the magnetic axis, which is perpendicular to c, leads to a crystal symmetry reduction from hexagonal to monoclinic. The observed magnitude of the magnetic moment of the Tb ion is 1.5 mu(B), unusually small relative to the free ion and parent compound (TbCo3B2) values. These magnetic and crystal properties are discussed and compared with what was previously published for the parent compound. © 2008, Elsevier Ltd.