Spin-glass-like behaviour and magnetic order in Mn[CrGa]S spinels

T. Groń , J. Krok-Kowalski , A.W. Pacyna , T. Mydlarz

Magnetization and susceptibility were investigated as a function of temperature and magnetic field in polycrystalline Mn[CrGa]S spinel. The dc susceptibility measurements at 919Oe showed a disordered ferrimagnetic behavior with a Curie-Weiss temperature =-55K and an effective magnetic moment of 5.96 μ close to the spin-only value of 6.52 μ for Cr and Mn ions in the 3 and 3 configurations, respectively. The magnetization measured at 100Oe revealed the multiple magnetic transitions with a sharp maximum at the Néel temperature =3.9K, a minimum at the Yafet-Kittel temperature =5K, a broad maximum at the freezing temperature =7.9K, and an inflection point at the Curie temperature =48K indicating a transition to paramagnetic phase. A large splitting between the ZFC and FC magnetizations at a temperature smaller than suggests the presence of spin-glass-like behaviour. This behaviour is considered in a framework of competing interactions between the antiferromagnetic ordering of the (Mn) sublattice and the ferromagnetic ordering of the (Cr) sublattice.

Mots clés: A. Spin glass; B. Ferrimagnetic ordering; C. Chalcogenide

T. Groń, J. Krok-Kowalski, A.W. Pacyna, T. Mydlarz. Spin-glass-like behaviour and magnetic order in Mn[CrGa]S spinels. Journal of Physics and Chemistry of Solids, 2009, 70 (5), pp.900. ⟨10.1016/j.jpcs.2009.04.016⟩. ⟨hal-00543154⟩