1ST-PRINCIPLES STUDY OF THE MAGNETIZATION DENSITY IN CEFE2

We present first-principles calculations of the magnetization density and its resolution into spin and orbital moments in CeFe2. The calcula tions do not rely on any shape assumptions concerning the density or p otential and verify that the total moment on the Ce and Fe sites are c oupled antiparallel. This is due to the fact that the Fe and Ce spin m oments are coupled antiparallel and that the orbital moment on the Ce site is smaller than the spin moment. We argue that this is in sharp c ontrast to the expected behavior for a 4f local moment system, where e ssentially the free-ion behavior of the Ce magnetism is expected, with an orbital moment larger and antiparallel to the spin moment. The rec ent suggestion of a large nonspherical moment density in CeFe2 is spec ifically addressed and the calculations are found to support such a be havior. The calculated individual moments are approximately 50% larger than the moments deduced from neutron-scattering experiments.