NUMERICAL CALCULATION OF THE CHARGE STATE AND ELECTROSTATIC POTENTIAL OF A BINARY NANOCLUSTER STRUCTURE WITH SI2ZNS CELLS IN A CUBIC LATTICE OF CRYSTALLINE SILICON WITH A DIAMOND STRUCTURE

Numerical calculation of electronic and atomic structures of complex systems of crystalline and transitional nano- and micro-sizes by using quantum physical methods will make it possible to forecast new properties of crystalline silicon with various concentrations of clusters of impurity atoms, structural arrangement at lattice sites and types of clusters. The quantum-chemical method was used to calculate the required characteristics of the cell, i.e. the charge state and electrostatic potential for the base matrix of Si (silicon) and silicon with an impurity cluster consisting of 3 tetrahedral cells type- Si2ZnS in the base lattice of Si. Calculation of the electrostatic potential of the base lattice of Si, and silicon with an impurity cluster of Si2ZnS in the Si lattice revealed a noticeable change in the potential intensity at the cell sites. In the cluster, charge transfer occurs from S (sulfur) atoms to Zn (zinc) atoms. Zn atoms at sites acquire a negative charge while S atoms acquire a positive charge. In fact, the numerical calculation confirms the hypothesis that instead of completing its structure to the most stable electronic configuration ... s2p6, in certain cases the chalcogen atom can also donate some of its electrons to form a quasi-stable configuration ... sp3.

Влияние решеточного и спин-фононного вкладов на температурное поведение расщепления основного состояния Gd-=SUP=-3+-=/SUP=- в SrMoO-=SUB=-4-=/SUB=-

The temperature behavior of the EPR spectra of the Gd^3+ impurity center in single crystals of SrMoO_4 in the temperature range T = 99–375 K is studied. The analysis of the temperature dependences of the spin Hamiltonian b _2 ^0 ( T ) = b _2( F ) + b _2( L ) and P _2 ^0 ( T ) = P _2( F ) + P _2( L ) (for Gd^157) describing the EPR spectrum and contributing to the Gd^3+ ground state splitting Δ E is carried out. In terms of the Newman model, the values of b _2( L ) and P _2( L ) depending on the thermal expansion of the static lattice are estimated; the b _2( F ) and P _2( F ) spin-phonon contributions determined by the lattice ion oscillations are separated. The analysis of b _2 ^0 ( T ) and P _2 ^0 ( T ) is evidence of the positive contribution of the spin-phonon interaction; the model of the local oscillations of the impurity cluster with close frequencies ω describes well the temperature behavior of b _2( F ) and P _2( F ).