1. Slavica Maletić, Univerzitet u Beogradu, Fizički fakultet, Studentski trg 12, Beograd, Serbia
2. Dušan Popović, Univerzitet u Beogradu, Fizički fakultet, Studentski trg 12, Beograd, Serbia
3. Jablan Dojčilović, Univerzitet u Beogradu, Fizički fakultet, Studentski trg 12, Beograd, Serbia
The subject of our research is study of the effects of various treatments on the structural and spectral characteristics of oxide (Y3Al5O12, SrTiO3 and Al2O3) belonging to the group of ionic crystals with wide energy band gap. We have investigated the dielectric and optical characteristics of laser single crystals of Y3Al5O12 (YAG) doped by ions from the group of iron (3d-), Al2O3 single crystals and SrTiO3 crystals doped by 3d and 4f- ions. Dielectric properties of the investigated single crystals were analyzed using dielectric spectroscopy (100 kHz - 15 MHz) in a wide temperature range (50-300 K). The comparison of the temperature dependence of the dielectric permittivity (εr) and dielectric loss (tanδ) at different test frequencies for undoped and doped crystals have been performed. The optical properties were studied on the basis of the absorption spectra in the UV-Vis region. Experimental results showed that the presence of 3d dopants in YAG crystal causes displacement of the absorption edge and the appears of characteristic peaks. The differences observed in the absorption spectra were probably the result of the incorporation of 3d ions on two possible symmetrically different positioning of aluminum ions; tetrahedrical and octahedrical, in the YAG crystal lattice. The dielectric spectroscopy measurements for samples of SrTiO3 doped by 4f ions show the anomalous behaviors of the dielectric permittivity at temperatures around the temperature of the structural phase transition 105 K.
Thematic field:
SIMPOZIJUM A - Nauka materije, kondenzovane materije i fizika čvrstog stanja
Date:
29.06.2016.
Contemporary Materials 2016 - Savremeni Materijali
Paper file
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