Structural modifications in titania-doped tantalum pentoxide crystals: a Raman scattering study

Laser heated pedestal growth and optical characterization of CaTa2O6 single crystal fiber

“…To the best of our knowledge, the literature contains no reports of the Raman spectrum for cubic CaTa 2 O 6 ; hence, we have no means of attributing the lines to the vibration modes. However, we found that, from [27]. Moreover, the lines at 167, 270, 243 and 650 cm À1 were also in agreement with those reported for the orthorhombic phase of CaTa 2 O 6 [26].…”

Effect of Eu2O3 doping on Ta2O5 crystal growth by the laser-heated pedestal technique

“…5(b). The same monoclinic to triclinic phase transition was already observed in Ta 2 O 5 fibers doped with lower amount of Tm ions (1 at% Tm 2 O 3 ) doped fibers [14]. This behavior suggests that the phase transition is dependent on the rare earth ion nature and content.…”

“…Ta 2 O 5 undergoes several phase transitions in response to heating and cooling. As a result, it is difficult to grow single phase Ta 2 O 5 crystals from the melt because their crystalline structure is strongly dependent on processing conditions and impurities [14]. During heating process, the low temperature phase (orthorhombic) undergoes a phase transition at 1360 1C [15] into a high temperature phase with a tetragonal symmetry.…”

Hydrogen production over Fe-doped tantalum oxide from an aqueous methanol solution under the light irradiation

“…It has been reported by the literature [15] that Ta 2 O 5 crystal has partial properties of ionic compound. The molecular structure of tantalum oxide has been expressed as cluster model of TaO n 5À2n , where n ranges from 4 to 8, corresponding to T d , D 3h , O h , D 5h , D 6h and D 3d symmetric groups [16,17]. Thus the Raman spectra of tantalum oxide are rather complex.…”