| Electrical resistivity, specific heat, magnetic susceptibility, and magnetization of the crystalline approximant Cd(6)Sm are investigated in a temperature range 1.8-300 K. Both structural and magnetic transitions are clearly evidenced. A sharp structural phase transition is observed at T(c) = 179 K in the electrical resistivity as well as in the specific heat, which is attributed to orientational ordering of the Cd(4) tetrahedron located at the center of the icosahedral cluster. In addition, three successive magnetic transitions are found at T(M1) = 12.5, T(M2) = 10.2, and T(M3) = 6.5 K. The anomaly at T(M1) is attributed to an antiferromagnetic transition, whereas those at T(M2) and T(M3) are to ferrimagnetic transitions. The observation of the ferrimagnetic orders indicates that (pseudo) icosahedra made of localized Sm spins have a nonzero net magnetic moment, and the moments of the magnetic clusters form a long-range magnetic order. |
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