Papers by Author: Jiang Shen

Abstract: Interfacial potential of Fe [110]/TMC[001] (TM=V, Nb and Ta) are obtained with adhesive energy and the inversion method. The interfacial stability and tensile fracture properties of the semi-coherent interfaces of the Fe [110]/TMC[001] (TM=V, Nb and Ta) are studied based on the interfacial potentials. Results indicated that Fe/VC interface is more stable than the Fe/TMC (TM=Nb and Ta) interfaces.

Abstract: The structural and elastic properties of B2 ScAl doped with Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag and Cd elements are studied by using first-principles calculations. The calculated elastic coefficients of pure ScAl are consistent with other theoretical results. The results of elastic constants indicate that all the ScAl-based alloys discussed are mechanically stable. The bulk modulus B, shear modulus G, Youngs modulus Y, Pugh ratio B/G and Cauchy pressure (C₁₂-C₄₄) are investigated. It is found that the addition of Ru that prefers Al site in ScAl can increase the stiffness of ScAl and improve its ductility.

Abstract: Interfacial atomic structure of iron and transitional metal carbides interface systems were investigated by first-principle method. Meanwhile, free surfaces of iron and transition metal carbides were also researched, and systematically analyzed the differences of atomic moving behaviors of two interfacial systems. These calculations indicated that the atomic movements of transitional metal carbides were lesser than softer iron matrix in these interfacial systems.

Abstract: The phase stability and site preference of transition metal carbides Cr in Fe7-xCrxC3 are studied based on the pair potentials obtained by the lattice inversion method. The lattice constants and cohesive energy of Fe7-xCrxC3 with the content x are calculated. The results show that Cr atoms substitute for Fe with a strong preference for the 6c1 sites and the order of site preference is 6c1, 6c2 and 2b. Calculated lattice parameters are in good agreement with the experimental data. Moreover, the total and partial phonon densities of states are first evaluated for the Fe7-xCrxC3 compounds with the hexagonal structure. We also provide some information on the vibrational properties of transition metal carbides, such as the specific heat and Debye temperature were also evaluated.

Abstract: We systematically performed first-principles investigations of the structural properties, electron energy band, and densities of states (DOS) for ThO2. All calculations were carried out using the local density approximation (LDA), generalized gradient approximation (GGA), LDA+U, and GGA+U approaches. We also compared our findings with experimental data and other calculations. The lattice parameter obtained using the GGA+U agrees well with the experimental value.

Abstract: The effect of cobalt on the structural properties of intermetallic Tb₃(Fe_28-xCo_x)V_1.0 with Nd₃(Fe,Ti)₂₉ structure has been studied by using interatomic pair potentials obtained through the lattice inversion method. Calculated results show that the order of site preference of cobalt is 8j(Fe8), 4e(Fe11) and 2c(Fe1) which is in good agreement with experimental results. And the calculated lattice constants coincide quite well with experimental values. All these prove the effectiveness of interatomic pair potentials obtained through the lattice inversion method in the description of rare-earth materials.

Abstract: We explored a new type alloy EAM potential (CLI-EAM) that the value of atomic electron density and pair potential between distinct atoms are obtained by Chen’s lattice inversion based on first-principles calculations. The alloy CLI-EAM potential acquired from NiAl alloy can also apply in Ni3Al successfully and the results of basic properties agreed with the experiments. The results of formation energy of point defects of NiAl and Ni₃Al alloy indicate that the structural defects are anti-site defects of Al when enrichments of Al atoms.

Abstract: We systematically investigated the structural stability and electronic properties of silicene-like nanotubes by potassium atoms encapsulated using density functional theory. The calculations show that all the structures of KnSi8(n+1) (n=2-12) nanowires are stable, the structural stable is proportional to the lengths of the nanowires. Electronic population analysis shows that K atoms gain electrons and Si atoms lose electrons as a whole, some electrons transferred from Si to K atoms. Because the peaks of d levels in DOS are contribution from the 3d hybridization levels of K and Si atoms, the magnetic moments derived from the orbitals hybridization. Maybe these kinds of nanowires will play an important role in spintronics and nanoelectronics.

Abstract: We explored a new type EAM potential (CLI-EAM) that the value of atomic electron density and pair potential functions are obtained by Chen’s lattice inversion based on first-principles calculations. This EAM potential is applied to Cu, Ag, Cu and Pt metals successfully and the results of basic properties agreed with the experiments. For the same metal, the cohesive energy of fcc structures are the lower than bcc structures.

Abstract: The structural stability and electronic properties of silicene-like nanotubes by metal atoms encapsulated were studied by first-principles. The calculations demonstrate that all the structures of nanotubes are stable, expect beryllium doped. Some nanotubes are semiconductor with small value of band gap while others are conductor, because the interaction and hybridizations decrease the band gap. Our electronic structure analysis shows that metal atoms gain electrons and Si atoms lose electrons as a whole, some electrons transferred from Si to metal atoms. We hope that our calculations will provide help to further experimental studies.