Show simple item record

dc.creatorLazarevic, Zorica
dc.creatorRomcevic, Nebojsa
dc.creatorVijatović Petrović, Mirjana
dc.creatorStojanović, Biljana
dc.date.accessioned2023-12-07T06:58:02Z
dc.date.available2023-12-07T06:58:02Z
dc.date.issued2009
dc.identifier.urihttp://rimsi.imsi.bg.ac.rs/handle/123456789/2724
dc.description.abstractThe infrared spectra of ABO3 perovskites have been studied extensively. Factor group analysis for BaTiO3 with cubic symmetry (space group Pm3m : O6r) predicts only infrared bands (three triply degenerate infrared active modes of F1o symmetry) and one optically silent (neither infrared nor Raman active) mode of F2u symmetry. The three infrared active modes are commonly called the stretching modes (B-O bond-length modulation), and the external mode in which the 8Oo octahedron vibrates against the I atoms. In tetragonal symmetry (space group P4mm : C4v), 12 fundamental optical modes with the following irreducible representation are expected: 3Ab 4E and Br [2,3]. The perovskite structure has capability to host ions of different size, so a large number of different dopants can be accommodated in the BaTiO3 lattice that makes BaTiO3 semiconductive. Doping of BT ceramics is very important for obtaining very interesting characteristics for potential applications. The aim of this study is to investigate the influence of La- and Sb- doping on the BaTiO3 synthesized through the Pechini method. Infrared spectroscopy was used in addition to the XRD, Raman spectroscopy and SEM investigations in order to find evidence of the structural phase in undoped and doped BaTiO: ceramics' BaTiO3 powders were prepared by the polymeric organometallic precursors method (Pechini process) using barium and titanium citrates and for doping were used lanthanum nitrate and antimony acetate. The powders were isostatically pressed into pellets 8 mm in diameter and average thickness of about 2.5 mm at pressure of 98.1 MPa. Sintering was performed at 1300'C for 8 h and the heating rate was 10 oC/min with nature cooling in an air atmosphere. Far-infrared reflectivity measurements were made in spectral range (50-700 cm-1; at room temperature with BOMEM DA8 spectrometer. Figure 1 show the IR spectrum of the BaTiO3 and La- and Sb-doped BaTiO3 ceramics sintered at 1300C for 8 h. The bands in the lower wave number range (50-700 cm-1) are due to Ti-O vibrations. The characteristic peak is found for all samples. The modes at 180 and 470 cm-r belong to the At representation to which the soft phonon mode associated with the ferroelectric phase transition at Tc - 395 K belongs. The broad band over 50-180 cm-' is due to soft phonon. Because of the over damped character of the soft phonon, it is difficult to determine the frequency. The intensity of three peaks of the doped BT 0.5 mol% Sb, undoped barium titanate and BT doped 0.5 mol % La appear on 183, 184 and 185 cm-1, respectively, intensities of the mode's at 180, 250 and 470 cm-t decrease for BaTio3 and La- and Sb-doped BaTiO3:, respectively. The modes at 382' 439 and 612 cm-t can be observed in case Sb- doped BaTiO3. This suggests a change of crystal structure. These results are in agreement with our previous investigations [4]. All observations related to IR indicate the formation of pure single phase of BT and La and Sb doped BT.sr
dc.language.isoensr
dc.publisherFinal Workshop COST 539, 28-30 October 2009, Aveiro, Portugal, Programme and book of extended abstracts, p 78-79sr
dc.rightsopenAccesssr
dc.sourceFinal Workshop COST 539, 28-30 October 2009, Aveiro, Portugal, Programme and book of extended abstracts, p 78-79sr
dc.subjectinfrared spectrasr
dc.subjectBaTiO3sr
dc.subjectPechini methodsr
dc.subjectIR spectrumsr
dc.subjectcrystal structuresr
dc.titleINFRARED SPECTROSCOPY OF UNDOPED AND LA AND Sb DOPED BaTiO3 PREPARED BY POLYMERIC PRECURSORS METHODsr
dc.typeconferenceObjectsr
dc.rights.licenseARRsr
dc.identifier.fulltexthttp://rimsi.imsi.bg.ac.rs/bitstream/id/7075/bitstream_7075.pdf
dc.identifier.rcubhttps://hdl.handle.net/21.15107/rcub_rimsi_2724
dc.type.versionpublishedVersionsr


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record