[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.