The NMR device with a magnet utilizes a composition exhibiting a desired value of magnetic susceptibility, wherein the composition comprises a metal ion selected from the group consisting of Gd.sup.+3, Fe.sup.+3 and Mn.sup.+2 and an amorphous material using a ligand or chelating agent to solubilize the metal ion throughout the marphous material, wherein the magnetic susceptibility of the composition exhibits a desired value at cryogenic temperatures such as nearly zero susceptibility at temperatures at or below 77 K.