We calculated the vibrational free energies of the selected ordered compounds in the Ag-Cu system by using two kinds of methods: (1) calculating the phonon dispersion and density of states and the consequently vibrati...We calculated the vibrational free energies of the selected ordered compounds in the Ag-Cu system by using two kinds of methods: (1) calculating the phonon dispersion and density of states and the consequently vibrational free energies by using the method of ab initio inverted interatomic potentials and dynamic matrix;(2) the vibrational free energies determined by a Debye-Griineisen approximation. The Ag-Cu phase diagram is calculated by the cluster variation method. The results show that the solubility at Ag-rich end of the calculated phase diagram considering vibrational modes by using the first method is in better agreement with the experimental.展开更多
We proposed a simple analytical interatomic potential model by extending the framework of embedded-atom model to include the non-central three-body potentials. This model can be easily applied to treat transition meta...We proposed a simple analytical interatomic potential model by extending the framework of embedded-atom model to include the non-central three-body potentials. This model can be easily applied to treat transition metals and their alloys based on the very recently developed lattice inversion method. We used the model to calculate the phonon density of states and entropy of Fe3AI, and the results were in agreement with the experimental data.展开更多
The series expansion approach has been employed to calculate the exact energy spectra of hydrogenic donor states in a quantum-dot quantum well(QDQW). The result shows that the hydrogenic donor energy levels are very d...The series expansion approach has been employed to calculate the exact energy spectra of hydrogenic donor states in a quantum-dot quantum well(QDQW). The result shows that the hydrogenic donor energy levels are very different from those in a quantum dot. In a QDQW, the donor energy levels depend on not only the radius of core and the barrier, but also the numbers of small wells. When there exist two small wells outside the core, the “band gap”exists between donor levels, and its width depends on the depth of the small wells.展开更多
By using the variational method and the dielectric continuum model,we investigate the effect of electric Held on the intrasubband scattering rates of electron-surface optical phonon.The results show that the scatterin...By using the variational method and the dielectric continuum model,we investigate the effect of electric Held on the intrasubband scattering rates of electron-surface optical phonon.The results show that the scattering rates tend to increase with the electric field strength.These scattering rates become significant for wide quantum well wire and sufficiently high fields.展开更多
基金Supported in part by the National Natural Science Foundation of China under Grant No.19725417and the National PANDENG Project under Grant No.95-YU-41.
文摘We calculated the vibrational free energies of the selected ordered compounds in the Ag-Cu system by using two kinds of methods: (1) calculating the phonon dispersion and density of states and the consequently vibrational free energies by using the method of ab initio inverted interatomic potentials and dynamic matrix;(2) the vibrational free energies determined by a Debye-Griineisen approximation. The Ag-Cu phase diagram is calculated by the cluster variation method. The results show that the solubility at Ag-rich end of the calculated phase diagram considering vibrational modes by using the first method is in better agreement with the experimental.
基金the Doctoral Foundation of Educational Ministry of China。
文摘We proposed a simple analytical interatomic potential model by extending the framework of embedded-atom model to include the non-central three-body potentials. This model can be easily applied to treat transition metals and their alloys based on the very recently developed lattice inversion method. We used the model to calculate the phonon density of states and entropy of Fe3AI, and the results were in agreement with the experimental data.
基金the Doctoral Fund of the State Education Commission of China under Grant No.96002703.
文摘The series expansion approach has been employed to calculate the exact energy spectra of hydrogenic donor states in a quantum-dot quantum well(QDQW). The result shows that the hydrogenic donor energy levels are very different from those in a quantum dot. In a QDQW, the donor energy levels depend on not only the radius of core and the barrier, but also the numbers of small wells. When there exist two small wells outside the core, the “band gap”exists between donor levels, and its width depends on the depth of the small wells.
文摘By using the variational method and the dielectric continuum model,we investigate the effect of electric Held on the intrasubband scattering rates of electron-surface optical phonon.The results show that the scattering rates tend to increase with the electric field strength.These scattering rates become significant for wide quantum well wire and sufficiently high fields.
