Anisotropic Exchange Interactions in UNiGe

摘要

UNiGe crystallizing in the orthorhombic TiNiSi-type of structure orders magnetically below T(sub N)= 50 K with an additional magnetic phase transition at 42 K. Both structures (below 42 K commensurate antiferromagnetic, between 42 K and T(sub N) incommensurate) are non- collinear with significant a-axis component ((mu)(sub x) = 0.35 (mu)(sub B)U at 20 K). The magnetic properties are highly anisotropic both in the ordered and the paramagnetic state. There are two metamagnetic transitions both with the field applied along the b- and the c-axis. While the magnetic structure above the second metamagnetic transition is forced ferromagnetic for both field orientations, for the field applied along the a-axis the magnetization curve at 4.2 K is linear up to 38 T and no change in magnetic structure is observed.