H 53 Hemmati, M. Structure of liquid Al2O3 from a Computer Simulation Model [Text] / M. Hemmati, M. Wilson, P. A. Madden // The Journal of Physical Chemistry B. - 1999. - V. 103, N 20. - P4023-4028. - Bibliogr.: 29 ref. . - ISSN 1089-5647 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): Al2O3 -- Al -- АЛЮМИНИЙ -- ОКСИД АЛЮМИНИЯ -- ОКСИДЫ ЖИДКИЕ -- ЖИДКИЕ ОКСИДЫ -- МОДЕЛИРОВАНИЕ КОМПЬЮТЕРНОЕ -- СТРУКТУРА ОКСИДОВ -- КОМПЬЮТЕРНОЕ МОДЕЛИРОВАНИЕ -- ХИМИЯ Аннотация: The combination of new containerless sample and high intensity synchrotron source technologies has enabled the X-ray diffraction pattern from a molten oxide (Al2O3) to be determined for the first time. Here we show that the liquid-state diffraction pattern, predicted from a computer simulation with a potential derived from the ground-state crystal structure, agrees very well with the experimental data. Analysis of the local structure in the simulated melt shows that the Al(3+) ions are not predominantly tetrahedrally coordinated, as surmised in the experimental study. Rather, six-, five- and four- coordinate Al(3+) ions are found. Furthermore, evidence is presented for a tendency of the different coordinate species to spatially separate, and it is suggested that Al2O3 is close to a liquid-liquid phase separation of the type recently discussed by Angell and co-workers |