O ct 1 99 9 The Debye - Waller factor in solid 3 He and 4

Debye - Waller factor in solid 3 He and 4

The Debye-Waller factor and the mean-squared displacement from lattice sites for solid He and He were calculated with path-integral Monte Carlo at temperatures between 5 and 35 K, and densities between 38 and 67 nm. It was found that the mean-squared displacement exhibits finite-size scaling consistent with a crossover between the quantum and classical limits of N and N, respectively. The tempe...

Debye - Waller factor measurements of solid 3 He and 4

X-ray synchrotron radiation was used to measure Debye-Waller factors of helium crystals for both He and He in both hcp and fcc phases. To our knowledge, there are no previous measurements for He. The ranges studied for He and He crystals were 11.52–12.82 and 10.95–12.13 cm, respectively, and 11.5–18.2 and 12.0–20.3 K. With small uncertainty, only a Gaussian dependence upon momentum transfer Q w...

O ct 1 99 9 Investigation of 4 He 3 trimer on the base of Faddeev equations in configuration space

Relation of Vacancy Formation and Migration Energies to the Debye Temperature in Solids

A derivation of the relation between the vacancy formation energy E,, the migration energy E, and the Debye temperature 0c is presented. In the Debye model, the relation between E, and Bc follows directly from the “dynamical” form of diffusion theories. The relation between E, and Bc is obtained for solids obeying a corresponding states law. The Debye temperature appearing in the derived expres...

Neutrino - pair bremsstrahlung by electrons in neutron starcrustsA

Neutrino-pair bremsstrahlung by relativistic degenerate electrons in a neutron-star crust at densities 10 9 g cm ?3 < < 1:5 10 14 g cm ?3 is analyzed. The processes taken into account are neutrino emission due to Coulomb scattering of electrons by atomic nuclei in a Coulomb liquid, and electron-phonon scattering (the phonon contribution) and Bragg diiraction (the static-lattice contribution) in...