Within the confines of the standard model of rare earth magnetism, the high temperature magnetic properties of rare earth ions in a crystalline environment are identical to the magnetic behaviour of free tri-positive rare earth ions. At low temperatures deviations from free-ion behaviour occur due to the action of an anisotropic crystalline electric field (CEF). For Pr3+-ions in a low symmetry crystalline environment it is expected that the 9-fold degeneracy of the spin orbit coupled ground state multiplet associated with the free tri-positive ion should be completely uplifted by the CEF yielding a non-magnetic singlet ground state for the Pr3+ 4f-electrons. PrNiGe2 is known to order ferromagnetically despite the fact that the Pr3+ ions occupy the low-symmetry m2m sites in the CeNiSi2-type structure. This has prompted the current study into the ground state properties of PrNiGe2. The structure of the CEF-split energy levels in this system could be determined from specific heat measurements. The analyses point to the formation of a pseudo-doublet ground state in the system, and we forward a conceptual explanation of the observed magnetic order in PrNiGe2 in terms a fortuitous merging of electronic singlet levels into a local level dispensation of higher degeneracy.
|Consider for a student <br> award (Yes / No)?||Yes|
|Level (Hons, MSc, <br> PhD, other)?||PhD|
|Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?||Yes|