Mn55NMR Study of Local-Moment Formation inCuMn

Abstract

NMR shifts and relaxation times are reported here for ${}_{}{}^{55}{}_{}{}^{}\mathrm{Mn}$ impurity nuclei in a series of liquid ${\mathrm{Al}}_{1-x}{\mathrm{Cu}}_x$:Mn alloys over the composition range $0<~x<~1$ and at temperatures from 1050 to 1425 K. Analysis of shifts and susceptibilities reveals abrupt changes in $d$-spin hyperfine field and orbital susceptibility at the Cu-rich end. A sharply increased value of the relaxation rate for $x\to 1$ is analyzed to give $J_{\mathrm{sd}}=0.82\mathrm{} \mathrm{and} 1.22$ eV for the liquid and solid phases, respectively.