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CreatorTitleDescriptionSubjectDate
1 Chaudhuri, Reaz A.Three-dimensional singular stress field at the front of a crack and lattice crack deviation (LCD) in a cubic single crystal plateA novel eigenfunction expansion technique, based in part on separation of the thickness variable, is developed to derive three-dimensional asymptotic stress fields in the vicinity of the front of a semi-infinite through-crack weakening an infinite plate made of a homogeneous cubic single crystal. C...2010-05-12
2 Liu, FengSelf-consistent tight-binding methodA self-consistent tight-binding formalism is described. The self-consistency is achieved by the introduction of a chemical hardness matrix and a generalization of the Huckel model to make the tight-binding Hamiltonian an implicit functional of the charge density. Studies of the band structures of d...Tight-binding method; Self-consistency; Huckel model1995-10
3 Liu, FengMagnetism of Al-Mn quasicrystalsThe effect of symmetry and concentration of Mn on the magnetism of Al-Mn quasicrystals has been investigated through self-consistent density-functional calculations using molecular clusters and supercell band-structure schemes. A single Mn atom surrounded by 54 Al atoms in an icosahedral or a cuboct...Al-Mn quasicrystals; Self-consistent; Density-functional calculations1993-07
4 Liu, FengQuantum size effect on the magnetism of finite systemsThe magnetic moments of the ferromagnetic transition metals Fe, Co, and Ni confined to one-dimensional chains are found to fluctuate with increasing chain length before converging to the infinite limit. This quantum size effect is derived from a simple first-principles theory that we have developed...Quantum size; Finite systems; Ferromagnetic transition metals; Magnetic moments; Fe; Co; Ni; Molecular-orbital approach1990-07
5 Liu, FengQuantum size effect on adatom surface diffusionUsing scanning tunneling microscopy, we demonstrate that the nucleation density of Fe islands on the surface of nanoscale Pb films oscillates with the film thickness, providing a direct manifestation of the quantum size effect on surface diffusion. The Fe adatom diffusion barriers were derived to be...Quantum size effect; QSE; Adatoms; Surface diffusion; Fe islands; Nanoscale metallic structures; Epitaxial growth; Pb films2006-12
6 Liu, FengOrigin of intergranular embrittlement of Al alloys induced by Na and Ca segregation: grain boundary weakeningUsing a first-principles computational tensile test, we show that the ideal tensile strength of an Al grain boundary (GB) is reduced with both Na and Ca GB segregation. We demonstrate that the fracture occurs in the GB interface, dominated by the break of the interfacial bonds. Experimentally, we f...Intergranular embrittlement; Grain boundary; Intergranular fracture2006-06
7 Liu, FengMagnetism and local order II: self-consistent cluster calculationsThe effect of the local environment on the magnetic moment and its convergence to bulk value has been studied self-consistently by using a molecular-cluster model within the framework of spin-density-functional theory. We show that the magnetic moment of the central atom in clusters of 43 Ni atoms a...Local order; Magnetic moment; Molecular-cluster model; Spin-density-functional theory1989-07
8 Tiwari, AshutoshMid- to long-wavelength infrared surface plasmon properties in doped zinc oxidesThis work investigates properties of surface plasmons on doped metal oxides in the 2-20 μm wavelength regime. By varying the stoichiometry in pulse laser deposited Ga and Al doped ZnO, the plasmonic properties can be controlled via a fluctuating free carrier concentration. This deterministic approa...2012-01-01
9 Scarpulla, MichaelPulsed and continuous wave solid phase laser annealing of electrodeposited CuInSe2 thin filmsCu(In,Ga)Se2 (CIGS) thin film photovoltaic absorber layers are primarily synthesized by vacuum based techniques at industrial scale. In this work, we investigate non-vacuum film synthesis by electrochemical deposition coupled with pulsed laser annealing (PLA) and or continuous wave laser annealing (...2012-01-01
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