Nuclear magnetic resonance of samarium in Sm xY 2− xCo 17

Abstract

The very-well-resolved spin echo nuclear magnetic resonance spectra of 147Sm and 149Sm in Sm x Y 2− x Co 17 compounds at 4.2 K are presented. From the spectra the values of the hyperfine field and the quadrupole splitting at the Sm site in these compounds are obtained. A step-like change in the quadrupole splitting is observed between Sm 0.1Y 1.9Co 17 and Sm 0.2Y 1.8Co 17, with only slight variations between other compounds. The effect is assigned to a change in the easy magnetization direction from the basal plane in Sm 0.1Y 1.9Co 17 to the c axis in Sm 0.2Y 1.8Co 17. The change in easy magnetization direction has been used to obtain from the quadrupole splittings the separate contributions to the electric field gradient from the 4f electrons and the lattice. The lattice contribution has been used to derive the sign and magnitude of the crystal electric field coefficient A 2 o at the Sm site in these compounds.