Quadrupolar interactions in heavy fermion metal YbRh2Si2

We describe the experimentally revealed by Sichelschmidt et al, Phys. Rev. Lett. 91 (2003) 156401, g tensor, g_perpendicular=3.561 and g_parallel=0.17, at 5 K by means of crystal field interactions of the 4f13 configuration of the Yb3+ ion of YbRh2Si2 in a slightly orthorhombically distorted tetragonal crystal field. We have shown that the temperature dependence of the quadrupolar interactions Q(T) of the Yb nucleous will help to distinguish between Gamma_7 and Gamma_6 ground state. For the Gamma_7 ground state Q(T) is expected to exhibits an anomalous dependence. Keywords: heavy fermion, crystal field, quadrupolar moment,YbRh2Si2Comment: 2 pages LaTeX(Elsevier Science class), 1 figur

Orbital moment in CoO and in NiO

The total, orbital and spin moment of the Co2+ ion in CoO has been calculated within the quasi-atomic approach with taking into account strong correlations, crystal-field interactions and the intra-atomic spin-orbit coupling. The orbital moment of 1.39 \mu B amounts at 0 K, in the magnetically-ordered state, to more than 34% of the total moment (4.01 \mu B). The same calculations yield for NiO the orbital and total moment of 0.46 \mu B and 2.45 \mu B, respectively. PACS No: 71.70.E; 75.10.D Keywords: 3d magnetism, crystal field, spin-orbit coupling, orbital moment, CoO, NiOComment: 6 pages in tex+3 figs, submitted for PNSXM-03, Venic