Structural analysis of nanocrystalline BaTiO3

Synthesis and Structural Characterization of Nanocrystalline Batio3 at Various Calcination Temperatures

“…The appearance of strong Raman peaks near 307 cm -1 (B1 mode) that corresponds to tetragonal BTO phase is contradictory with the cubic symmetry observed in the XRD analysis, for which no first-order Raman activity is expected. This apparent contradiction was resolved in our previous work [6] where we showed using theoretical calculation within the Density Functional Theory framework that the Raman spectroscopy is a technique highly sensitive to the molecular level, being able to detect distortion about 0.5 pm in the crystalline structure of BTO.…”

“…As it is known, Raman spectroscopy is a highly sensitive technique to probe the local structure of BTO samples [6,13,14]. Figure 3 shows the Raman spectra of BTO samples under different times of calcination.…”

“…Raman spectra showed the presence of the tetragonal phase, in contrast with the XRD results that showed only the presence of a cubic phase. However, this controversy was solved in a previous work [6], where it was established that Raman spectroscopy is a sensitive technique and is able to detect small distortions in the crystalline structure of the BTO and, the active mode to 307 cm -1 can be used to detect the presence of the tetragonal phase. In addition, various calcination treatments were made to BTO powders with the purpose to improve their ferroelectric properties.…”

“…The characterization techniques based on the crystal symmetry, such as the Raman spectroscopy can detect crystallographic distortions and defects at the molecular level [5]. In the case of BTO it has been demonstrated theoretically that the technique is able to detect distortions in the order of 0.5 pm [6].…”

“…Taking into account the benefits of wet routes for the synthesis of e-mail: lpadilla@uantof.cl BTO and a high sensitivity to the symmetry of Raman spectroscopy as was established in a previous paper [6], the goal of the present work is to study the BTO nanoparticles obtained by the sol-gel hydrothermal synthesis method, as well as to study the changes in the nanoparticles and their effects at different times and calcination temperatures, characterizing them by means of various experimental techniques, such as XRD and TEM, and fundamentally by means of Raman spectroscopy. In addition, from theoretical calculations the electronic structure will be obtained for both, tetragonal and cubic phases, to establish general properties that characterize both phases.…”