- The ternary RE-Si-B systems (RE = Dy, Ho, Er and Y) at 1270 K: Solid state phase equilibria and magnetic properties of the solid solution REB2-xSix (RE = Dy and Ho)
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The solid state phase equilibria in the ternary RE-Si-B diagrams (RE = Dy, Ho, Er and Y) were determined at 1270 K using experimental techniques such as X-ray diffraction, scanning electron microscopy and electron probe microanalysis. In general, three ternary phases were obtained for each diagram: the line compound RE5Si2B8 with tetragonal symmetry, the boron-inserted Nowotny phase RE5Si3Bx of Mn5Si3-type and the solid solution REB2-xSix of AlB2-type. Prior to this work, the binary systems RE-Si and RE-B, which form the boundary of each diagram, were also re-investigated. In addition to the structures of RE5Si3 (Mn5Si3-type, RE = Dy, Ho and Y) and Dy3Si4 (Ho3Si4-type) which were previously reported or will be presented in a forthcoming paper, the X-ray single crystal structures of RE5Si4 (Sm5Ge4-type, RE = Dy and Ho), DySi (CrB-type) and HoSi in both polymorphic modifications, i.e. the FeB- (high temperature) and CrB- (low temperature) types, were determined and are described herein. Structural relationships between members of the same series on one side, and between both forms of HoSi on the other side, are also discussed in terms of coordination polyhedra and interatomic distances. Finally, magnetic measurements were performed on the alloys REB2-xSix, which in case of RE = Dy exhibit a marked increase of the magneto-crystalline anisotropy, whereas for RE = Ho a change from ferromagnetic to antiferromagnetic behaviour with increasing silicon content is encountered.
- Roger, Jérome,Babizhetskyy, Volodymyr,Guizouarn, Thierry,Hiebl, Kurt,Guérin, Roland,Halet, Jean-Fran?ois
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- Single Crystal Growth and Properties of Incongruently Melting TbB6, DyB6, HoB6, and YB6
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Details of the single crystal growth of incongruently melting TbB6, DyB6, HoB6, and YB6using a crucible-free vertical floating zone method are reported. Magnetic susceptibility is reported and discussed. It is suggested that antiferro-quadrupolar ordering occurs in DyB6between 30 and 25.6 K.
- Takahashi,Kunii
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- Large crystal structure distortion in DyB6 studied by X-ray diffraction
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A large magnetoelastic coupling induces a lattice distortion of a rhombohedral type in DyB6. Below the quadrupolar ordering temperature TQ=31K the cubic and the distorted phases coexist. The cubic phase disappears at 23K, which was identified as the magnetic ordering point TN. In the magnetic phase the distortion (dl/l)111 increases monotonically with decreasing temperature and reaches the value of 9 × 10-3 at 8 K, which is one of the largest value known for cubic compounds.
- Granovsky,Markosyan
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- Thermodynamic functions for heavy rare-earth hexaborides as measured by calorimetry in the temperature range from 5 to 300 K
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The molar heat capacities of gadolinium, terbium, and dysprosium hexaborides were measured over the temperature range 5-300 K. The temperature dependences and the standard values of the enthalpy, entropy, and the Gibbs energy were calculated by taking into account the nuclear contribution to the heat capacity.
- Sirota,Novikov,Vinokurov
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p. 1722 - 1725
(2007/10/03)
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- Dy-Ni-B System
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Based on x-ray diffraction data, the 1070-(0-33 mol % Dy) and 870-K (33-100 mol % Dy) sections of the Dy-Ni-B phase diagram were constructed. The existence of 13 ternary borides was confirmed, and two new borides with the tentative compositions Dy2Ni2B and Dy3Ni8B9 and unidentified structures were obtained. The coordination polyhedra and configurations of boron atoms in the borides of the Dy-Ni-B system are examined. The phase relations in the systems Ln-Ni-B (Ln = yttrium group rare earth)are analyzed
- Chaban, N. F.,Kuz'ma, Yu. B.
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p. 476 - 479
(2008/10/08)
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