Nuclear Magnetic Resonance in Rare-Earth—Aluminum Intermetallic Compounds: RAl3

The Knight shifts of the ²⁷Al NMR in LaAl₃, CeAl₃, PrAl₃, NdAl₃, GdAl₃, and TbAl₃ have been measured at temperatures from 78° up to 450°K. The effective exchange constants $\mathcal{J}$ between the 4f electrons localized at the rare‐earth ions and the conduction electrons at the Al nuclei have been derived to be −0.2 eV. Ruderman—Kittle—Yosida periodic oscillations of the conduction electron polarization have been used to relate the results with those obtained for RAl₂. Nuclear quadrupole coupling constants have been measured to be |e²qQ|=0.8 Mc/sec. On the basis of the ionic point model e²qQ has been calculated for RAl₃ and RAl₂.