The Influence of Partial Isomorphic Substitution on Electronic and Optical Parameters of ABSO_{4} Group Crystals |

P.A. Shchepanskyi
^{a,b}, V.M. Gaba^{ c}, V.Yo. Stadnyk^{ a}, M.Ya. Rudysh^{a,b}, R.S. Brezvin^{ a} and M. Piasecki^{ b}^{a}Faculty of Physics, Ivan Franko National University of Lviv, 8 Kyrylo-and-Mefodii Str., UA-79005 Lviv, Ukraine
^{b}Institute of Physics, Jan Dlugosz Academy, Armii Krajowej 13/15, PL-42201, Czestochowa, Poland
^{c}National University "Lviv Politechnic", 5 Mitropolit Andrei Str., UA-79013 Lviv, Ukraine |

Full Text PDF |

First principles calculations of band energy, density of states and dielectric function of K_{1.75}(NH_{4})_{0.25}SO_{4} single crystals in Pnma structure is performed in the framework of density functional theory. In order to describe the exchange-correlation interaction the general gradient approximation and local density approximation are used. Character and genesis of main energy bands of the crystal are discussed and comparison with data set for K_{2}SO_{4} isomorphic crystal performed. The influence of partial isomorphic substitution K→ NH_{4} found itself mainly in altering the bottom of conduction band and decrease of band gap value. From the dielectric functions dependences, the refractive indices dispersion and absorption coefficient spectra are deduced. Obtained refractive indices satisfactorily agree with experimental data in the visible spectrum region. |

DOI: 10.12693/APhysPolA.133.781 PACS numbers: 71.20.-b, 77.84.-s, 77.84.Bw |