Nuclear magnetic resonance detection of the nuclear spins near paramagnetic impurities in solids

It was shown that on applying two radio-frequency fields, both of the same amplitude, one rotating at the frequency ωI for nuclei inside the diffusion barrier and one rotating at the frequency ωS for nuclei outside the diffusion barrier, the Hartmann-Hahn condition will be reached, which results in conservation of Zeeman energy in the spin-diffusion process and destruction of the spin-diffusion barrier. This technique can be used to detect the nuclear magnetic resonance signal from the nuclei located near paramagnetic impurities. (author)