Journal
JOURNAL OF PHYSICS-CONDENSED MATTER
Volume 28, Issue 3, Pages -Publisher
IOP Publishing Ltd
DOI: 10.1088/0953-8984/28/3/035801
Keywords
crystal structure; phase stability; electronic structure; wide-gap semiconductor; Ta2O5
Categories
Funding
- Centro de Investigaciones-Instituto Tecnologico Metropolitano (Colombia)
- FAPESP (Brazil)
- CNPq (Brazil)
- CIEN-CODI-Vicerrectoria de Investigacion-Universidad de Antioquia (Colombia)
Ask authors/readers for more resources
Tantalum pentoxide (Ta2O5) is a wide-gap semiconductor that presents good catalytic and dielectric properties, conferring to this compound promising prospective use in a variety of technological applications. However, there is a lack of understanding regarding the relations among its crystalline phases, as some of them are not even completely characterized and there is currently no agreement about which models better explain the crystallographic data. Additionally, its phase diagram is unknown. In this work we performed first-principles density functional theory calculations to study the structural properties of the different phases and models of Ta2O5, the equation of state and the zone-centered vibrational frequencies. From our results, we conclude that the phases that are built up from only distorted octahedra instead of combinations with pentagonal and/or hexagonal bipyramids are energetically more favorable and dynamically stable. More importantly, this study establishes that, given the pressure range considered, the B-phase is the most favorable structure and there is no a crystallographic phase transition to another phase at high-pressure. Additionally, for the equilibrium volume of the B-phase and the lambda-model, the description of the electronic structure and optical properties were performed using semi-local and hybrid functionals.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available