|Ultima descărcare din IBN:|
| SM ISO690:2012|
STRONSKI, Alexander; PAIUK, Oleksandr; NASIEKA, Iu.; GUDYMENKO, A.; GUBANOVA, Antonina; LISHCHYNSKYY, I.; VLCEK, Miroslav. Properties of chalcogenide glasses doped by transition and rare-earth elements. In: Materials Science and Condensed Matter Physics. Editia a 7-a, 16-19 septembrie 2014, Chișinău. Chișinău, Republica Moldova: Institutul de Fizică Aplicată, 2014, p. 115.
|Materials Science and Condensed Matter Physics
Editia a 7-a, 2014
Conferința "Materials Science and Condensed Matter Physics" |
Chișinău, Moldova, 16-19 septembrie 2014
In present work the results on the influence of doping by transitional and rare earth elements on thermal, optical, luminescent, structural and magnetic properties of chalcogenide glasses are presented. Chalcogenide glasses doped with transitional and rare earth elements were synthesized by common melt-quenching technique using constituent elements of 6N purity which were melted in vacuumsealed silica ampoules for 10-12 hours and subsequently quenched in air. Thermal properties (Tg values for undoped and doped glasses) were studied using DSC technique. Activation energy of glass transition was estimated with the use of Kissinger‘s expression. Structural studies were carried with the use of Raman and IR spectroscopy and X-ray diffraction. The amorphous nature of the bulk samples was confirmed by absence of sharp peaks in X-ray diffraction pattern. Radial electron distribution functions in doped and undoped bulk glasses were obtained and analyzed. In Raman spectra main observed effect under the introduction of dopants was the change of relative concentration of main and non-stoichiometric structural units characteristic for As2S3 glasses. Luminescence of As2S3 glass doped by Cr was studied in 800-1600nm region (T=77K, ex 514nm). Luminescence intensity increased with the Cr concentration thus showing on the increased level of defects with the chromium introduction. Glasses of As-S system modified by Yb have two bands of luminescence in near IR region (near 980 and 1060nm, excitation on 980nm wavelength, room temperature). In this case transitions are observed which are characteristic for Yb3+ ion. Investigation of influence of transition metals (Mn and Cr) dopants on the optical properties of As2S3 glass was studied in mid-IR region. Intensity of the vibrational absorption bands of various structural molecular fragments essentially depends on the chemical composition of glasses. The observed changes are considered to be connected with the interaction of the introduced dopants with the non-stoichiometric structural elements present in glass and inherent impurities of the host glass such as hydrogen and oxygen. Pure chalcogenide glasses are diamagnetics. Introduction of transitional and rare earth impurities changes the magnetic properties of investigated chalcogenide glasses. In the fields near 5T the M(T) dependence was observed which is characteristic for paramagnetics and ferromagnetics in the paramagnetic temperature range.