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...

A new thermodynamically self-consistent (TSC) method, based on the quasi-harmonic approximation (QHA), is used to obtain the Debye temperatures of LiFePO4 (LFP) and FePO4 (FP) from available experimental specific heat capacities for a wide temperature range. The calculated Debye temperatures show an interesting critical and peculiar behavior so that a steep increase in the Debye temperatures is...

Mixed crystals of alkali halides find applications in optical, optoelectronics and electronic devices. In the present study the pure and mixed crystals of NaClx NaBry-x KCl1-y were grown from the aqueous solution. The grown crystals were characterized by taking XRD, TG/DTA and Vicker’s hardness measurement. The Debye temperature is an important parameter of a solid. Several methods of evaluatin...

We consider the properties of l-dimensional gauge field-theories at finite temperatures and densities. The massive Schwinger model in the presence of a uniform charge background is shown to form a Wigner crystal which Debye screens charged impurities. The two species Schwinger model with oppositely charged fermions is studied at finite baryon density. This system does not undergo a phase transi...

We present an alternative way to calculate the screening of the static potential between two charges in (non)abelian gauge theories at high temperatures. Instead of a loop expansion of a gauge boson self-energy, we evaluate the energy shift of the vacuum to order e 2 after applying an external static magnetic field and extract a temperature-and momentum-dependent dielectric permittivity. The Ha...

The temperature dependence of the first three interlayer distances of the Ag(111) surface was studied by low-energy electron diffraction (LEED) over the temperature range 128K to 723 K. The first three interlayer spacings and the effective Debye temperatures were extracted from the LEED analysis. At the lowest temperature, the first two interlayer spacings are slightly (0.5 %) contracted. All t...

The temperature dependence of the motion of light interstitials is calculated using the quantum theory of Flynn and Stoneham. The results are compared with the asymptotic expressions given previously. They show that the high temperature asymptote is accurate over a wider range of temperature than expected, whereas the low temperature form is of very restricted application. Deviations from the a...