MAGNETIC-PROPERTIES OF THE SUPERCONDUCTING ALLOY SYSTEM (CE1-CHOC)RU2 - NEUTRON-SCATTERING STUDY

Neutron scattering measurements have been carried out on the superconducting alloy system (Ce1-cHoc)Ru2 for c = 0.10, 0.32 and 0.38 as a function of temperature and magnetic field. The observed crystal-field transitions for all concentrations are found to be very similar and can be understood on the basis of a cubic crystal field acting on the Ho3+ (J = 8), with W = +0.03 meV and x = -0.3. The Ho ground state is thus established to be the magnetic G{cyrillic}5 triplet over the entire composition range of interest. Small-angle scattering data taken on an alloy with 38% Ho, in which a conventional ferromagnetic transition was anticipated, show that indeed ferromagnetic correlations develop at low temperatures. However, no characteristic peak in the intensity vs. temperature was observed; rather the intensity at small wavevectors Q continues to increase slowly down to the lowest temperatures attained (1.05 K), while little intensity change is observed below T {reversed tilde} 2K at larger Q (0.05 → 0.15 A ̊-1). © 1979.