[kragen]

As I understand it, the magnetic field doesn't have to be voluminous; it just has to be strong and uniform. It can be arbitrarily small as long as it's large compared to an atom, which is why benchtop NMR machines can exist at all, though they won't ever be truly miniature unless either we can also miniaturize the cryostats and refrigerant supply, or we can find a usable room-temperature superconductor. Am I misunderstanding something? As I said, you know a lot more about this than I do.

[dekhn]

NMR is an ensemble measurement technique. You can't measure the magnetic moment of a single molecule. Instead, you need a highly pure sample and lots of it. That has to be in solvent (I'm leaving out solid spinning NMR here, that's a different ballgame entirely), enough solvent to keep the sample in solution.

I think you're wasting your time trying to improve NMR. The value of the technique isn't worth it.