Understanding the magnetic ground state of rare-earth intermetallic compound Ce 4Sb 3: Magnetization and neutron diffraction studies

R. Nirmala (1) , A. V. Morozkin (2) , Olivier Isnard (3) , A. K. Nigam

1 Department of Mathematics [Madras]
2 MSU - Lomonosov Moscow State University
3 NEEL - MRS - Matériaux, Rayonnements, Structure

Magnetization and neutron diffraction studies have been performed on Ce 4Sb 3 compound (cubic Th 3P 4-type, space group I4¯3d, no. 220). Magnetization of Ce 4Sb 3 reveals a ferromagnetic transition at ˜5 K, the temperature below which the zero-field-cooled and field-cooled magnetization bifurcate in low applied fields. However, a saturation magnetization ( MS) value of only ˜0.93 μB/Ce 3+ is observed at 1.8 K, suggesting possible presence of crystal field effects and a paramagnetic/antiferromagnetic Ce 3+ moment. Magnetocaloric effect in this compound has been computed using the magnetization vs. field data obtained in the vicinity of the magnetic transition, and a maximum magnetic entropy change, -Δ SM, of ˜8.9 J/kg/K is obtained at 5 K for a field change of 5 T. Inverse magnetocaloric effect occurs at ˜2 K in 5 T indicating the presence of antiferromagnetic component. This has been further confirmed by the neutron diffraction study that evidences commensurate antiferromagnetic ordering at 2 K in zero magnetic field. A magnetic moment of ˜1.24 μB/Ce 3+ is obtained at 2 K and the magnetic moments are directed along Z-axis.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

R. Nirmala, A. V. Morozkin, Olivier Isnard, A. K. Nigam. Understanding the magnetic ground state of rare-earth intermetallic compound Ce 4Sb 3: Magnetization and neutron diffraction studies. Journal of Magnetism and Magnetic Materials, 2009, 321, pp.188-191. ⟨10.1016/J.JMMM.2008.08.102⟩. ⟨hal-00984928⟩