Elmassalami M, Moreno R, Saeed RM, Chaves FAB, Chaves CM, Rapp RE, Takeya H, Ouladdiaf B, Amara M. On the ferromagnetic structure of the intermetallic borocarbide TbCo(2)B(2)C.
JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009;
21:216006. [PMID:
21825571 DOI:
10.1088/0953-8984/21/21/216006]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Based on magnetization, specific heat, magnetostriction and neutron-diffraction studies on single-crystal TbCo(2)B(2)C, it is found out that the paramagnetic properties, down to liquid nitrogen temperatures, are well described by a Curie-Weiss behavior of the Tb(3+) moments. Furthermore, below T(c) = 6.3 K, the Tb sublattice undergoes a ferromagnetic (FM) phase transition with the easy axis being along the (100) direction and, concomitantly, the unit cell undergoes a tetragonal-to-orthorhombic distortion. The manifestation of an FM state in TbCo(2)B(2)C is unique among all other isomorphous borocarbides, in particular TbNi(2)B(2)C (T(N) = 15 K, incommensurate modulated magnetic state) even though the Tb ions in both isomorphs have almost the same crystalline electric field properties. The difference among the magnetic modes of these Tb-based isomorphs is attributed to a difference in their exchange couplings which are in turn caused by a variation in their lattice parameters and in the position of their Fermi levels.
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