Intensity anomalies have been found in the nuclear magnetic resonance of I127 in NaI and KI single crystals when the magnetic field is along a [1,0,0] type direction. The intensity enhancement in these cases indicates a collapse of the satellite transitions (m → m − 1, m ≠ ☒) into the central transition (m = ☒ → m = −☒). It is concluded that the crystals contain edge and∕or screw dislocations which are preferentially oriented along [1,1,0] and [1,0,0] type directions, respectively. The degree of orientation is greater in NaI than in KI.
These studies afford an explanation of anomalous resonance line widths reported for NaI by other observers.