We show the results of first-principles calculations of structural,phonon,elastic,thermal and electronic properties of the Mg-X inter-metallics in their respective ground state phase and meta-stable phases at equilibr...We show the results of first-principles calculations of structural,phonon,elastic,thermal and electronic properties of the Mg-X inter-metallics in their respective ground state phase and meta-stable phases at equilibrium geometry and the studied pressure range.Phonon dispersion spectra for these compounds were investigated by using the linear response technique.The phonon spectra do not show any abnormality in their respective ground state phase.The respective ground states phases of the studied system remain stable within the studied pressure range.Electronic and thermodynamic properties were derived by analysis of the electronic structures and quasi-harmonic approximation.The mixed bonding character of the Mg-X intermetallics is revealed by Mg-X bonds,and it leads the metallic nature.Most of the contribution originated from X ions d like states at Fermi level compared to that of Mg ion in these intermetallics.In this work,we also predicted the melting temperature of these intermetallics and evaluated the Debye temperature by using elastic constants.展开更多
The rationality of characteristic crystals model has been expounded. Nine new Gibbs energy functions of CC theory have been established. The regular solution model corresponds to the simplest situation of CC model. An...The rationality of characteristic crystals model has been expounded. Nine new Gibbs energy functions of CC theory have been established. The regular solution model corresponds to the simplest situation of CC model. Any G-functions of CC theory can be used to represent liquid and fcc phases of Ag-Cu system. The lattice stability parameters of characteristic crystals for Ag-Cu alloys can be described with the form accepted by the SGTE group. Only when we have made studies on the law of change of energy, volume and electronic structure of the Ag-Cu system, can we choose the G-function correctly and then establish an integral knowledge system and the database, so as to lay a good foundation for the scientific design of new alloys.展开更多
基金The present work was financially supported by a Grant-Aid for Science and Engineering Research Board(Grant No.SERB/F/922/2014-15),Department of Science&Technology,Government of India.
文摘We show the results of first-principles calculations of structural,phonon,elastic,thermal and electronic properties of the Mg-X inter-metallics in their respective ground state phase and meta-stable phases at equilibrium geometry and the studied pressure range.Phonon dispersion spectra for these compounds were investigated by using the linear response technique.The phonon spectra do not show any abnormality in their respective ground state phase.The respective ground states phases of the studied system remain stable within the studied pressure range.Electronic and thermodynamic properties were derived by analysis of the electronic structures and quasi-harmonic approximation.The mixed bonding character of the Mg-X intermetallics is revealed by Mg-X bonds,and it leads the metallic nature.Most of the contribution originated from X ions d like states at Fermi level compared to that of Mg ion in these intermetallics.In this work,we also predicted the melting temperature of these intermetallics and evaluated the Debye temperature by using elastic constants.
文摘The rationality of characteristic crystals model has been expounded. Nine new Gibbs energy functions of CC theory have been established. The regular solution model corresponds to the simplest situation of CC model. Any G-functions of CC theory can be used to represent liquid and fcc phases of Ag-Cu system. The lattice stability parameters of characteristic crystals for Ag-Cu alloys can be described with the form accepted by the SGTE group. Only when we have made studies on the law of change of energy, volume and electronic structure of the Ag-Cu system, can we choose the G-function correctly and then establish an integral knowledge system and the database, so as to lay a good foundation for the scientific design of new alloys.
