Analysis of optical magnetoelectric effect in GaFeO_3

We study the optical absorption spectra in a polar ferrimagnet GaFeO_3. We consider the E1, E2 and M1 processes on Fe atoms. It is shown that the magnetoelectric effect on the absorption spectra arises from the E1-M1 interference process through the hybridization between the 4p and 3d states in the noncentrosymmetry environment of Fe atoms. We perform a microscopic calculation of the spectra on a cluster model of FeO_6 consisting of an octahedron of O atoms and an Fe atom displaced from the center with reasonable values for Coulomb interaction and hybridization. We obtain the magnetoelectric spectra, which depend on the direction of magnetization, as a function of photon energy in the optical region 1.0-2.5 eV, in agreement with the experiment.Comment: 18 pages, 5 figure

Phytochemical, microbiological, and technological studies in the field of obtaining a hydroalcoholic extract with antimicrobial activity from the liquorice root

Phytochemical composition and antimicrobial activity of hydroalcoholic extracts from the liquorice root with the use of different concentrations of ethanol have been studied. The optimal range of ethanol concentration of 65±15% v/v has been found. The dependency between the integral index of antimicrobial activity of the extract and concentration of glycyram and licuroside has been foun