Ytterbium ESR in a lattice with weak coupling: the case of YbPt2Sn

We observed a well-defined Yb3+ electron spin resonance (ESR) line in YbPt2Sn. The single crystal ESR data show strongly anisotropic g factors, being largest in the basal plane, in agreement with magnetization data. This proves the intrinsic nature of the ESR signal. Analysis of these results indicates the crystal electric field ground state to be the Γ7 doublet. Although the Kondo and intersite interactions are at least one order of magnitude weaker than in the Kondo lattices YbRh2Si2 and YbIr2Si2, the temperature dependence of linewidth and g factors show qualitative similarities.