相关论文: The Debye-Waller Factor in solid 3He and 4He
The mean square atomic displacement in hcp-phase solid He-4 has been measured in crystals with a molar volume of 21.3 cm^3. It is temperature independent from 1 K to 140 mK, with no evidence for an anomaly in the vicinity of the proposed…
The Debye-Waller factor has been calculated for stabilized delta-phase plutonium with 5% aluminum. A quasi-harmonic Born-von Karman force model with temperature dependent phonon frequencies was used to calculate the mean-square thermal…
This paper presents a first-principles study of the Debye-Waller factor and the Debye temperature for amorphous silicon ($a$-Si) from lattice-dynamical calculations and direct molecular-dynamics simulations using density-functional theory…
We present some theoretical results on the lattice vibrations that are necessary for a concise derivation of the Debye-Waller factor in the harmonic approximation. First we obtain an expression for displacement of an atom in a crystal…
Prompted by recent experimental developments, a theory of surface scattering of fast atoms at grazing incidence is developed. The theory gives rise to a quantum mechanical limit for ordered surfaces that describes coherent diffraction peaks…
We show that in YVO3 new hard phonons gradually become zone center active below ~210 K verifying that a lattice phase transition takes place at about that temperature. The Debye-Waller factor found from EXAFS measurements show an additional…
An approach is presented for theoretical calculations of the Debye-Waller factors in x-ray absorption spectra. These factors are represented in terms of the cumulant expansion up to third order. They account respectively for the net thermal…
We theoretically study the stability of the solidified second-layer 3He at 4/7 of the first-layer density adsorbed on graphite, which exhibits quantum spin liquid. We construct a lattice model for the second-layer 3He by taking account of…
Displacements of atoms and molecules away from lattice sites in helium and parahydrogen solids at low temperature have been studied by means of Quantum Monte Carlo simulations. In the bcc phases of He-3 and He-4, atomic displacements are…
High-resolution neutron backscattering techniques are exploited to study the elastic and quasi-elastic response of the high-density amorphous (HDA), the low-density amorphous (LDA) and the crystalline ice Ic upon temperature changes. Within…
We report the first application of x-rays to the measurement of the temperature dependent Bragg peak intensities to obtain Debye-Waller factors on high-temperature superconductors. Intensities of (0,0,l) peaks of YBa2Cu3O7 and HgBa2CaCu2O6…
This note has no new results and is therefore not intended to be submitted to a "research" journal in the foreseeable future, but to be available to the numerous individuals who are interested in this issue. The Debye-Waller factor is the…
In this paper we demonstrate that the weak temperature dependence of structure factor of supercooled liquids, a defining feature of the glass transition, is a consequence of the averaging of the scattering intensity either due to the use of…
A new quantum-theoretical derivation of the elastic and inelastic scattering probability of He atoms from a metal surface, where the energy and momentum exchange with the phonon gas can only occur through the mediation of the surface…
The dynamic structure factor of a harmonically trapped Bose gas has been calculated well above the Bose-Einstein condensation temperature by treating the gas cloud as a canonical ensemble of noninteracting classical particles. The static…
Solid He4 is viewed as a nearly perfect Debye solid. Yet, recent calorimetry indicates that its low-temperature specific heat has both cubic and linear contributions. These features appear in the same temperature range ($T \sim 200$ mK)…
We have measured the mass diffusion coefficient D of 3He in superfluid 4He at temperatures lower than were previously possible. The experimental technique utilizes scintillation light produced when neutron react with 3He nuclei, and allows…
We carried out quartz crystal microbalance experiments of a 5 MHz AT-cut crystal for superfluid 4He films on Grafoil (exfoliated graphite) with a small amount of 3He up to 0.40 atoms/nm2. We found that the mass decoupling from oscillating…
The vibrational entropy of a solid at finite temperature is investigated from the perspective of information theory. Ab initio molecular dynamics (AIMD) simulations generate ensembles of atomic configurations at finite temperature from…
Increasing power densities in integrated circuits has led to an increased prevalence of thermal hotspots in integrated circuits. Tracking these thermal hotspots is imperative to prevent circuit failures. In 3D integrated circuits,…