TDPAC study of a solid-state reaction doping process of 181Hf (→181Ta) impurities in the Ho2O3 semiconductor

D. RICHARD; E. L. MUÑOZ; G. N. DARRIBA; L. A. ERRICO; M. RENTERÍA

Ginebra

Conferencia; 3rd Joint International Conference on Hyperfine Interactions and International Symposium on Nuclear Quadrupole Interactions. HFI/NQI 2010; 2010

In this work we study the ball-milling-assisted solid-state reaction doping method between neutron-activated m-HfO2 and the bixbyite Ho2O3. In order to follow the doping process of 181Hf donor impurities in the semiconductor Ho2O3 and to elucidate the effect of each variable involved in theprocess, time-differential perturbed-angular correlation (TDPAC) experiments were carried out after each step of the doping process. The obtained hyperfine parameters were compared to those of m-HfO2, to those expected for Ho2O3 using a well established electric-field gradient (EFG) systematics for 181Ta in bixbyite sesquioxides, and to TDPAC results obtained in Ho2O3 samples doped by ion implantation of 181Hf(→181Ta). As we will show, we could determine the effect played by the milling and the thermal treatments, showing the capability of the TDPAC technique to follow the doping process and to give information about the inter-diffusion processes. We also demonstrate the excellent efficiency of the ball-milling-assisted solid-state reaction process to locate Hf donor impurities at the defect-free cationic sites of the Ho2O3 semiconductor, quantifying directly the amount of impurities doped after each step of the process.