NUCLEAR-MAGNETIC-RESONANCE OF SAMARIUM IN SMXY2-XCO17

The very-well-resolved spin echo nuclear magnetic resonance spectra of Sm-147 and Sm-149 in SmxY2-xCo17 compounds at 4.2 K are presented. Fr om the spectra the values of the hyperfine field and the quadrupole sp litting at the Sm site in these compounds are obtained. A step-like ch ange in the quadrupole splitting is observed between Sm0.1Y1.9Co17 and Sm0.2Y1.8Co17, with only slight variations between other compounds. T he effect is assigned to a change in the easy magnetization direction from the basal plane in Sm0.1Y1.9Co17 to the c axis in Sm0.2Y1.8Co17. The change in easy magnetization direction has been used to obtain fro m the quadrupole splittings the separate contributions to the electric field gradient from the 4f electrons and the lattice. The lattice con tribution has been used to derive the sign and magnitude of the crysta l electric field coefficient A2(0) at the Sm site in these compounds.