Structural and magnetic transitions in the crystalline approximant Cd6Sm

Tamura Ryuji

Muro Yuji

Hiroto Takanobu

Yaguchi Hiroshi

Beutier G.

Takabatake Toshiro

Physical Review B

Electrical resistivity, specific heat, magnetic susceptibility, and magnetization of the crystalline approximant Cd6Sm 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 Tc = 179 K in the electrical resistivity as well as in the specific heat, which is attributed to orientational ordering of the Cd4 tetrahedron located at the center of the icosahedral cluster. In addition, three successive magnetic transitions are found at TM1 = 12.5, TM2 = 10.2, and TM3 = 6.5 K. The anomaly at TM1 is attributed to an antiferromagnetic transition, whereas those at TM2 and TM3 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.

Physics [ 420 ]

eng

American Physical Society

(c) 2012 American Physical Society

[ISSN] 1098-0121

[DOI] 10.1103/PhysRevB.85.014203

[NCID] AA11187113

[DOI] http://dx.doi.org/10.1103/PhysRevB.85.014203