NMR/ON

We studied about the NMR method in one of the preceding chapters. The crucial point there was the very weak yet essential orientation of the nuclear ensemble. But what would happen if you do NMR on an ensemble of nuclei that is at very low temperature and therefore strongly oriented? This will lead to a method called Nuclear Magnetic Resonance on Oriented Nuclei (NMR/ON).

In the video, a picture was shown (repeated hereafter) with three experimental NMR/ON-spectra from which the value of the magnetic hyperfine field on Sr-impurity atoms in a bcc-Fe matrix was determined. Explain how you can deduce from these spectra the sign of the hyperfine field of Sr in iron, and put your thoughts in the forum underneath (in case you would not get to the full explanation, then try to formulate where you get stuck).