Satellite Free-Induction Signals in CdS:Mn

Satellite free-induction signals occurring ∼ ¼ μsec after the main free-induction signal have been observed during pulsed microwave experiments with ${\mathrm{Mn}}^{2+}$ in CdS. These signals also appeared flanking the echo in an electron spin-echo experiment and were ∼ 60 times weaker than the spin echo itself. When the Zeeman field was swept, the phase of the satellite signals underwent alternations, returning to any given value each time the field was changed by ∼ 1.4 G. It is shown that these satellites originate in the superhyperfine interaction of ${\mathrm{Mn}}^{2+}$ with the nuclei ${\mathrm{Cd}}^{111}$ and ${\mathrm{Cd}}^{113}$. The ease with which the satellites could be observed in spite of heavy broadening of the superhyperfine spectrum suggests that this may be a useful way of studying contact interactions in cases where the interaction is too weak to give a clearly resolved spectrum.