Mathematical modeling determination coefficient of magneto-optical absorption in semiconductors in presence of external pressure and temperature

The calculation of the coefficients of magneto-optical absorption in semiconductors at different temperatures and pressures is carried out. A formula for the temperature dependence of the oscillations of the combined density of states by the Kane dispersion law is obtained. Mathematical modeling has been carried out that determines the magneto-optical absorption coefficient in semiconductors in the presence of external influences. A new method for determining the magneto-optical absorption coefficient in semiconductors in the presence of pressure and temperature is proposed. The correspondence of simulation results with experimental data is shown.

Температурная зависимость автоволновых характеристик локализованной пластичности

The behavior of autowaves of localized plastic flow in the Fe-Ni-Cr alloy at temperatures of 143≤ T≤ 420 K is considered. The temperature dependence of the propagation velocity of the autowave is studied. It was found that for the region of low temperatures the inverse proportionality of the autowave velocity to the strain hardening coefficient and the quadratic dispersion law are fulfilled. The temperature independence of the elastoplastic deformation invariant is established.

Surface-state energies and wave functions in layered organic conductors

We have calculated and analyzed the surface-state energies and wave functions in quasi-two dimensional (Q2D) organic conductors in a magnetic field parallel to the surface. Two different forms for the electron energy spectrum are used in order to obtain more information on the elementary properties of surface states in these conductors. In addition, two mathematical approaches are implemented that include the eigenvalue and eigenstate problem as well as the quantization rule. We find significant differences in calculations of the surface-state energies arising from the specific form of the energy dispersion law. This is correlated with the different conditions needed to calculate the surface-state energies, magnetic field resonant values and the surface wave functions. The calculations reveal that the value of the coordinate of the electron orbit must be different for each state in order to numerically calculate the surface energies for one energy dispersion law, but it has the same value for each state for the other energy dispersion law. This allows to determine more accurately the geometric characteristics of the electron skipping trajectories in Q2D organic conductors. The possible reasons for differences associated with implementation of two distinct energy spectra are discussed. By comparing and analyzing the results we find that, when the energy dispersion law obtained within the tight-binding approximation is used the results are more relevant and reflect the Q2D nature of the organic conductors. This might be very important for studying the unique properties of these conductors and their wider application in organic electronics.

Damping of Magnetoelastic Waves

A general method for constructing a model of the dissipative function describing the relaxation processes induced by the damping of coupled magnetoacoustic waves in magnetically ordered materials has been developed. The obtained model is based on the symmetry of the magnet and describes both exchange and relativistic interactions in the crystal. The model accounts for the contributions of both the magnetic and elastic subsystems to the dissipation, as well asthe relaxation associated with the magnetoelastic interaction. The dispersion law for coupled magnetoelastic waves is calculated in the case of a uniaxial ferromagnet of the “easy axis” type. It is shown that the contribution of the magnetoelastic interaction to dissipative processes can play a significant role in the case of magnetoacoustic resonance.

MODEL FOR CALCULATION OF THE OPTICAL ABSORPTION SPECTRA OF SEMICONDUCTOR MATERIALS

A model for calculating the absorption spectra of semiconductor materials is presented. The model is based on the dispersion law calculation.

The Current Carriers’ Dispersion Law of a Crystal, Their Chemical Potential and a Set of Important Properties of Crystals

In this paper, a new non-parabolic dispersion law has been established, which for a small parameter of the spectrum nonparabolicity coincides with the known Kane’s nonparabolic dispersion law. The Kane’s dispersion law works well when the well-known parameter of nonparabolicity is much less than 1, and the new law works well enough when the parameter of nonparabolicity is less than 1. In addition, this law shows that crystals with a band gap (i.e., forbidden band width) Eg~10-1 eV – these are semiconductor crystals, crystals with Eg~10-2 eV – these are metals.