Based on 489 known perovskite-type complex oxides and a number of other type complex oxides, the pattern recognition-atomic parameter method is adopted to find regularities of the formation and the lattice distortion ...Based on 489 known perovskite-type complex oxides and a number of other type complex oxides, the pattern recognition-atomic parameter method is adopted to find regularities of the formation and the lattice distortion of the perovskite structure. It has been found that the restriction on Goldschmidt’s t factor constitutes only a necessary but not a sufficient condition to form perovskite-type compounds. A more effective mathematical model, which can precisely sum up the regularities of the formation, the lattice distortion, and the cell constants of known perovskite-type compounds and reliably make corresponding predictions on unknown compounds, can be set up by integrating multiple atomic parameters such as ionic radii, ionic valency, and Basanov’s electronegativity of constituent elements. Based on it, an intelligent database has been implemented. Its prediction accuracy is tested by eight newly discovered perovskite-type compounds such as Eu(Mn0.5 Ni0.5)O3, etc. (they are not included in the database展开更多
A four-parameter model based on the extended Miedema’s cellular model of alloy phases and pattern recognition methods has been used to study the regularities of the formation of binary intermetallic compounds between...A four-parameter model based on the extended Miedema’s cellular model of alloy phases and pattern recognition methods has been used to study the regularities of the formation of binary intermetallic compounds between tran-sition element and non-transition element. The formation criterion can be expressed as some inequities of electronega-tivity , the valence electron density in Wagner-Seitz cell nws1/3, Pauling’s metallic radius R and the number of valence electrons in atom Z or their functions. According to these empirical criterions, the 'unknown' binary alloy system can be predicted, the predicted result is better than that of Miedema’s two-parameter model.展开更多
基金This work was supported by the "863" Program (Grant No. 863-511-945-005).
文摘Based on 489 known perovskite-type complex oxides and a number of other type complex oxides, the pattern recognition-atomic parameter method is adopted to find regularities of the formation and the lattice distortion of the perovskite structure. It has been found that the restriction on Goldschmidt’s t factor constitutes only a necessary but not a sufficient condition to form perovskite-type compounds. A more effective mathematical model, which can precisely sum up the regularities of the formation, the lattice distortion, and the cell constants of known perovskite-type compounds and reliably make corresponding predictions on unknown compounds, can be set up by integrating multiple atomic parameters such as ionic radii, ionic valency, and Basanov’s electronegativity of constituent elements. Based on it, an intelligent database has been implemented. Its prediction accuracy is tested by eight newly discovered perovskite-type compounds such as Eu(Mn0.5 Ni0.5)O3, etc. (they are not included in the database
文摘A four-parameter model based on the extended Miedema’s cellular model of alloy phases and pattern recognition methods has been used to study the regularities of the formation of binary intermetallic compounds between tran-sition element and non-transition element. The formation criterion can be expressed as some inequities of electronega-tivity , the valence electron density in Wagner-Seitz cell nws1/3, Pauling’s metallic radius R and the number of valence electrons in atom Z or their functions. According to these empirical criterions, the 'unknown' binary alloy system can be predicted, the predicted result is better than that of Miedema’s two-parameter model.
