NMR of Nuclei near a Paramagnetic Impurity in Crystals

We report a new experimental NMR technique of wide applicability wherein the NMR of nuclei at crystalline sites near a localized paramagnetic impurity is directly observed. We find this method useful in determining electron-nuclear interactions and crystal structure, and as a site-selective probe of spin lattice relaxation, spin diffusion, and dynamic polarization processes for nuclei. We have applied this technique to Y(C₂H₅SO₄)₃·{}9H₂O doped with Yb³⁺ and Nd³⁺, CaF₂:Eu²⁺, and NH₄Cl:Cu²⁺(2H₂O).