Prediction of New Ground State Crystal Structure of Ta2O5

Abstract

Tantalum pentoxide (Ta2O5) is a wide-gap semiconductor which has important technological applications. Despite the enormous efforts from both experimental and theoretical studies, the ground state crystal structure of Ta2O5 is not yet uniquely determined. Based on first-principles calculations in combination with evolutionary algorithm, we identify a triclinic phase of Ta2O5, which is energetically much more stable than any phases or structural models reported previously. Characterization of the static and dynamical properties of the new phase reveals the common features shared with previous metastable phases of Ta2O5. In particular, we show that the d-spacing of ~ 3.8 Å found in the X-ray diffraction (XRD) patterns of many previous experimental works, is actually the radius of the second Ta-Ta coordination shell as defined by radial distribution functions.

25 Pages, 5 Figures, 3 Tables, plus one Supplemental Material

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Cited by in corpus (7)

• Global optimization of atomic structures with gradient-enhanced Gaussian process regression
• Effect of Ion Bombardment on the Chemical Properties of Crystalline Tantalum Pentoxide Films
• Ab initio simulation of $\mathrm{T}{\mathrm{a}}_2{\mathrm{O}}_5$: A high symmetry ground state phase with application to interface calculation
• Structural and Electronic Properties of Ta2O5 with One Formula Unit
• On the self-consistency of DFT-1/2
• Electronic Structure of Ta${}_2$O${}_5$ Polymorphs: Variation Trend of Band Gap and the Role of Oxygen Vacancies
• Ab initio Phase Diagram of Ta2O5