Magnetic structure of the ferromagnetic new ternary silicide Nd5CoSi2

• Published in: Journal of physics. Condensed matter Vol. 24; no. 13; p. 136001
• Main Authors: Mayer, C, Gaudin, E, Gorsse, S, Porcher, F, André, G, Chevalier, B
• Format: Journal Article
• Language: English
• Published: England 04-04-2012
• Subjects: Cobalt - chemistry; Magnetics; Magnets - chemistry; Neodymium - chemistry; Powder Diffraction; Silicon Compounds - chemistry
• ISSN: 1361-648X
• DOI: 10.1088/0953-8984/24/13/136001

Nd(5)CoSi(2) was obtained from the elements by arc-melting followed by annealing at 883 K. Its investigation by single-crystal x-ray and neutron powder diffraction shows that this ternary silicide crystallizes as Nd(5)Si(3) in a tetragonal structure deriving from the Cr(5)B(3)-type (I4/mcm space group; a = 7.7472(2) and c = 13.5981(5) Å as unit cell parameters). The structural refinements confirm the mixed occupancy on the 8h site between Si and Co atoms, as already observed for Gd(5)CoSi(2). Magnetization and specific heat measurements reveal a ferromagnetic behavior below T(C) = 55 K for Nd(5)CoSi(2). This magnetic ordering is further evidenced by neutron powder diffraction investigation revealing between 1.8 K and T(C) a canted ferromagnetic structure in the direction of the c-axis described by a propagation vector k = (0 0 0). At 1.8 K, the two Nd(3+) ions carry ordered magnetic moments equal respectively to 1.67(7) and 2.37(7) μ(B) for Nd1 and Nd2; these two moments exhibit a canting angle of θ = 4.3(6)°. This magnetic structure presents some similarities with that reported for Nd(5)Si(3).