Solid-State Reaction Doping Process of Hf Impurities in the Semiconductor C-Tm2O3 Monitored by TDPAC Spectroscopy

G.N. DARRIBA, L.A. ERRICO, E.L. MUÑOZ, AND M. RENTERÍA

Ciudad Autónoma de Buenos Aires, Argentina

Simposio; 15th International Symposium on Metastable, Amorphous and Nanostructured Materials (ISMANAM 2008); 2008

Comité Internacional (UBA-UNLP-CNEA-Univ. of Oxford)

<!-- /* Font Definitions */ @font-face {font-family:"CG Times"; panose-1:0 0 0 0 0 0 0 0 0 0; mso-font-alt:"Times New Roman"; mso-font-charset:0; mso-generic-font-family:roman; mso-font-format:other; mso-font-pitch:variable; mso-font-signature:3 0 0 0 1 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:none; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; layout-grid-mode:line;} p.MsoTitle, li.MsoTitle, div.MsoTitle {margin:0cm; margin-bottom:.0001pt; text-align:center; mso-pagination:none; tab-stops:0cm 439.45pt; font-size:14.0pt; mso-bidi-font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-GB; font-weight:bold; mso-bidi-font-weight:normal;} p.MsoBodyText2, li.MsoBodyText2, div.MsoBodyText2 {margin:0cm; margin-bottom:.0001pt; text-align:justify; mso-pagination:none; font-size:10.0pt; font-family:"CG Times"; mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:"Times New Roman"; layout-grid-mode:line;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> We show how γ-γ Time-Differential Perturbed-Angular-Correlation (TDPAC) experiments are an excellent test of the doping process of metallic impurities in oxide semiconductors performed by ball-milling-assisted solid-state reactions. The ionic exchange of donor Hf impurities insubstitutional cationic sites of the cubic (bixbyite) phase of the wide-gap semiconductor Thulium oxide was studied during a ball-milling-assisted solid-state reaction between C-Tm2O3 and neutron-activated m-HfO2. 181Ta atoms, obtained after the β- -decay of the 181Hf-isotope, were used as probes in TDPAC experiments carried out after each step of the doping process.The measured hyperfine interactions at 181Ta sites enabled the electric-field gradient tensor (EFG) characterization at representative Hf sites in each step of the doping process. The efficiency and substitutional character of the exchange process are discussed and elucidated in the frame of an empirical EFG systematic established in isostructural rare-earth oxides sharing thebixbyite structure.