³¹P nuclear magnetic resonance Knight shift and linewidth in Ni₃P and Cu₃P: a magic-angle spinning study

Abstract

Accurate measurements of small 31P Knight shift effects in crystalline Ni3P and Cu3P alloys have been performed by using a magic-angle spinning (MAS) nuclear magnetic resonance (NMR) technique. Both the average Knight shift and the width of its distribution have been found to be different when comparing a normal (equilibrium) and a melt-quenched Ni3P alloy and this is attributed to possible differences in defect concentration and grain size. The 31P NMR line shift of Cu3P is much smaller (K=0.012%) than that of Ni3P (K=0.179%) but spin-lattice relaxation time measurements indicated a Korringa-type relaxation mechanism for both alloys, i.e. Cu3P has also a metallic character.