Nuclear Magnetic Resonance Study in Cu-Ni Alloy

Abstract

The internal field or Knight shift and T 2 of Cu nucleus were measured in Cu-Ni alloys by spin-echo method in the whole concentration range. Ni resonance was measured for alloys containing less than 10 atomic percent of Cu. The internal field at the site of Cu nucleus in dilute Cu alloy is about -45 kOe and decreases with increasing concentration of Cu, c . The internal field at Ni nucleus decreases more slowly. The following model is proposed; the screening around Cu atoms is incomplete and only 0.4 part of one excess Cu electron goes into 3d holes of neighbouring Ni atoms. Cu has no d hole and the average moment of Ni decreases as (0.6- c )/(1- c ). The internal field at Cu nucleus is mainly caused by the negative polarization of the 4s electron at Cu nucleus induced by the magnetization of the nearest neighbouring Ni atoms.