Temperature dependence of the hyperfine fields of 111In in sapphire (Al2O3) single crystals

The decay of 111In to 111Cd via electron capture, accompanied by Auger electrons, leaves the outermost atomic shells of the cadmium in a highly ionized state. The recovery of the electron shells depends strongly on the electronic environment of the probe nucleus. In order to study this effect, sapphire single crystals were ion implanted with 111In at the Bonner Isotopenseparator. After annealing, the samples were measured at temperatures up to 900 K. To study the recombination characteristics and the influence of acceptor and donor levels, the samples were additionally doped with various concentrations of Si, Cr, Mg or P.