Nuclear magnetic resonance (NMR) is a wellestablished experimental method with applications in biology, chemical analysis, medical imaging, and fundamental research. Apart from the low intrinsic sensitivity in NMR, this technique suffers from two main drawbacks: First, the inability to observe signals through conductive material due to the low skin depth at high frequencies, with an exception of a few special cases, e.g. where the metal enclosure itself could be used as a resonator in a tuned circuit . Second, the significant spectral broadening in heterogeneous materials due to absolute field inhomogeneity.