Indirect observation of 235U-NMR in URh3

We propose a new method for 'indirectly' measuring ²³⁵U NMR parameters in uranium intermetallic compounds which contain ligand nuclei observable by NMR. The spin-echo decay of ¹⁰³Rh NMR has been measured in both ²³⁵U-enriched and non-enriched URh₃. It was found that the ²³⁵U enrichment in URh₃ induces an additional Lorentzian decay process for the ¹⁰³Rh nuclear spin-echo decay through unlike spin-spin coupling. This cross-relaxation effect allowed us to estimate the T₁ of ²³⁵U to be T₁T ~ 2 s K in URh₃. No such measurement has, to our knowledge, ever been reported for an actinide intermetallic compound.