Phase Transformations in the High‐Temperature Form of Pure and TiO₂‐Stabilized Ta₂O₅

Abstract

The high‐temperature forms of undoped tantalum pentoxide (H‐100Ta2O5) and TiO2–modified Ta2O5 (H‐92Ta2O5–8TiO2) were investigated by in situ synchrotron X‐ray diffraction and Raman scattering measurements. Two unquenchable and reversible phase transformations were observed in pure H‐Ta2O5, while only one was detected for TiO2‐stabilized H‐Ta2O5. Diffraction studies were consistent with displasive transformations, but hot‐stage Raman spectroscopy indicated the existence of transient intermediate forms during the transformations. Use of complementary techniques enabled the reinterpretation of phase transformations in light of a newly proposed crystal structure model for H‐Ta2O5,1 and emphasized the structural contributions of the oxygen sublattice.

The structure of niobium and tantalum oxides processed by concentrated light flux

“…7 demonstrates that the biggest changes are detected for the line vibrations [18]. It is also seen from Fig.…”

Densification and Grain Growth for Powder-Derived Ta2O5-TiO2 Ceramics

“…28 Extensive STEM EDS studies were carried out on thinned disks to probe any compositional variations that might occur in dense specimens produced from coated powders. No significant variation in the Ti:Ta ratio was observed across twin boundaries Fig.…”

Structural and optical properties of Ta2O5:Eu3+: Mg2+ or Ca2+ phosphor prepared by molten salt method

“…Ta 2 O 5 has attracted much attention of numerous researchers due to its remarkable optical, catalytic, dielectric and chemical properties [17]. Optically active rare earth doped Ta 2 O 5 films have been synthesized for the purpose of developing compact sources and amplifiers for the telecommunication applications [18][19].…”