| Journal: | Materials research |
| Database: | PERIÓDICA |
| System number: | 000312921 |
| ISSN: | 1516-1439 |
| Authors: | Oliveira, Terezinha Ferreira de1 Queiroz, Joaquim Carlos Barbosa Avillez, Roberto Ribeiro de2 Epprecht, Eugenio Kahn |
| Institutions: | 1Universidade Federal do Para, Departamento de Estatistica, Belem, Para. Brasil 2Pontificia Universidade Catolica do Rio de Janeiro, Rio de Janeiro. Brasil |
| Year: | 2006 |
| Season: | Oct-Dic |
| Volumen: | 9 |
| Number: | 4 |
| Pages: | 369-374 |
| Country: | Brasil |
| Language: | Inglés |
| Document type: | Artículo |
| Approach: | Analítico |
| English abstract | The present work uses multivariate statistical analysis as a form of establishing the main sources of error in the Quantitative Phase Analysis (QPA) using the Rietveld method. The quantitative determination of crystalline phases using x ray powder diffraction is a complex measurement process whose results are influenced by several factors. Ternary mixtures of Al2O3, MgO and NiO were prepared under controlled conditions and the diffractions were obtained using the Bragg-Brentano geometric arrangement. It was possible to establish four sources of critical variations: the experimental absorption and the scale factor of NiO, which is the phase with the greatest linear absorption coefficient of the ternary mixture; the instrumental characteristics represented by mechanical errors of the goniometer and sample displacement; the other two phases (Al2O3 and MgO); and the temperature and relative humidity of the air in the laboratory. The error sources excessively impair the QPA with the Rietveld method. Therefore it becomes necessary to control them during the measurement procedure |
| Disciplines: | Ingeniería, Física y astronomía |
| Keyword: | Ingeniería de materiales, Termodinámica y física estadística, Análisis multivariado, Método de Rietveld, Análisis cuantitativo de fases |
| Keyword: | Engineering, Physics and astronomy, Materials engineering, Thermodynamics and statistical physics, Multivariate analysis, Rietveld method, Quantitative phase analysis |
| Full text: | Texto completo (Ver HTML) |
