| Journal: | Materials research |
| Database: | PERIÓDICA |
| System number: | 000312430 |
| ISSN: | 1516-1439 |
| Authors: | Carvalho, J.F1 Franco, R.W.A2 Magon, C.J Nunes, L.A.O Pellegrini, F Hernandes, A.C |
| Institutions: | 1Universidade Federal de Goias, Instituto de Fisica, Goiania, Goias. Brasil 2Universidade de Sao Paulo, Instituto de Fisica de Sao Carlos, Sao Carlos, Sao Paulo. Brasil |
| Year: | 1999 |
| Season: | Abr |
| Volumen: | 2 |
| Number: | 2 |
| Pages: | 87-91 |
| Country: | Brasil |
| Language: | Inglés |
| Document type: | Artículo |
| Approach: | Descriptivo |
| English abstract | Visible and Infrared Optical Absorption and Electron Paramagnetic Resonance (EPR) techniques have been used to characterize the intrinsic defects in sillenite type crystals: nominally pure Bi12TiO20 (BTO) and doped with vanadium (BTO:V). Optical quality crystals, with the composition Bi12.04±0.08Ti0.76±0.07V0.16±0.02O20, have been grown. Results obtained by these different techniques have shown unambiguously the 5+ valence state of the vanadium ion in BTO:V crystals. In pure BTO samples, the EPR and optical spectra show strong evidence of the presence of the intrinsic defect BiM3+ + ho+, which consists of a hole h+, mainly located on the oxygen neighbors of the tetrahedrally coordinated Bi3+ ion. After doping with vanadium, results have shown that the characteristic bands, associated to this hole defect center, disappear, suggesting its transformation in single Bi3+. Anisotropy of the EPR spectra , at 20 K, is related to Fe3+ impurities |
| Disciplines: | Química, Ingeniería |
| Keyword: | Fisicoquímica y química teórica, Ingeniería electrónica, Resonancia paramagnética electrónica, Técnicas, Absorción óptica |
| Keyword: | Chemistry, Engineering, Physical and theoretical chemistry, Electronic engineering, Electron paramagnetic resonance, Techniques, Optical absorption |
| Full text: | Texto completo (Ver HTML) |
