First principles calculations of the electronic and dielectric properties of λ-Ta2O5
Ta2O5 is a wide-bandgap semiconductor that offers interesting applications in microwave
communications, mainly related to the manufacture of filters and resonators whose
size is inversely proportional to the dielectric constant of the material. For that reason, in
this work we present a theoretical study, based on density functional theory (using PBEsol
and hybrid HSE06 exchange-correlation functionals), of the electronic and dielectric
properties of the orthorhombic model -Ta2O5. We found that this model has a direct gap of
2.09 and 3.7 eV with PBEsol and HSE06, respectively. Furthermore, the calculated static
dielectric constant, 51, is in good agreement with the reported values of other phases of this
 R. J. Cava, “Dielectric materials for applications in microwave communications,” J. Mater. Chem., vol. 11, no. 1, pp. 54–62, 2001.
 K. J. Kumar, N. R. C. Raju, and A. Subrahmanyam, “Properties of pulsed reactive DC magnetron sputtered tantalum oxide (Ta2O5) thin films for photocatalysis,” Surf. Coatings Technol., vol. 205, pp. S261–S264, Jul. 2011.
 S. Pérez-Walton, C. Valencia-Balvín, A. C. M. Padilha, G. M. Dalpian, and J. M. Osorio-Guillén, “A search for the ground state structure and the phase stability of tantalum pentoxide,” J. Phys. Condens. Matter, vol. 28, no. 3, p. 035801, Jan. 2016.
 L. A. Aleshina and S. V Loginova, “Rietveld analysis of X-ray diffraction pattern from β- Ta2O5 oxide,” Crystallogr. Reports, vol. 47, no. 3, pp. 415–419, May 2002.
 A. Fukumoto and K. Miwa, “Prediction of hexagonal Ta2O5 structure by first-principles calculations,” Phys. Rev. B, vol. 55, no. 17, pp. 11155–11160, May 1997.
 R. Ramprasad, “First principles study of oxygen vacancy defects in tantalum pentoxide,” J. Appl. Phys., vol. 94, no. 9, pp. 5609–5612, Nov. 2003.
 R. Nashed, W. M. I. Hassan, Y. Ismail, and N. K. Allam, “Unravelling the interplay of crystal structure and electronic band structure of tantalum oxide (Ta2O5),” Phys. Chem. Chem. Phys., vol. 15, no. 5, pp. 1352–1357, 2013.
 W. Andreoni and C. A. Pignedoli, “Ta2O5 polymorphs: Structural motifs and dielectric constant from first principles,” Appl. Phys. Lett., vol. 96, no. 6, p. 062901, Feb. 2010.
 S. H. Lee, J. Kim, S.-J. Kim, S. Kim, and G.-S. Park, “Hidden Structural Order in Orthorhombic Ta2O5,” Phys. Rev. Lett., vol. 110, no. 23, p. 235502, Jun. 2013.
 A. Otero-de-la-Roza and V. Luaña, “Gibbs2: A new version of the quasi-harmonic model code. I. Robust treatment of the static data,” Comput. Phys. Commun., vol. 182, no. 8, pp. 1708–1720, Aug. 2011.
 A. Otero-de-la-Roza, D. Abbasi-Pérez, and V. Luaña, “Gibbs2: A new version of the quasiharmonic model code. II. Models for solid-state thermodynamics, features and implementation,” Comput. Phys. Commun., vol. 182, no. 10, pp. 2232–2248, Oct. 2011.
 J. P. Perdew et al., “Restoring the Density-Gradient Expansion for Exchange in Solids and Surfaces,” Phys. Rev. Lett., vol. 100, no. 13, p. 136406, Apr. 2008.
 J. Heyd, G. E. Scuseria, and M. Ernzerhof, “Hybrid functionals based on a screened Coulomb potential,” J. Chem. Phys., vol. 118, no. 18, pp. 8207–8215, May 2003.
 J. Heyd, G. E. Scuseria, and M. Ernzerhof, “Erratum: ‘Hybrid functionals based on a screened Coulomb potential,” J. Chem. Phys., vol. 124, no. 21, p. 219906, Jun. 2006.
 P. E. Blöchl, “Projector augmented-wave method,” Phys. Rev. B, vol. 50, no. 24, pp. 17953–17979, Dec. 1994.
 G. Kresse and D. Joubert, “From ultrasoft pseudopotentials to the projector augmented-wave method,” Phys. Rev. B, vol. 59, no. 3, pp. 1758–1775, Jan. 1999.
 G. Kresse and J. Furthmüller, “Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set,” Phys. Rev. B, vol. 54, no. 16, pp. 11169–11186, Oct. 1996.
 M. Gajdoš, K. Hummer, G. Kresse, J. Furthmüller, and F. Bechstedt, “Linear optical properties in the projector-augmented wave methodology,” Phys. Rev. B, vol. 73, no. 4, p. 045112, Jan. 2006.
 S. Pérez-Walton, C. Valencia-Balvín, G. M. Dalpian, and J. M. Osorio-Guillén, “Electronic, dielectric, and optical properties of the B phase of niobium pentoxide and tantalum pentoxide by first-principles calculations,” Phys. status solidi, vol. 250, no. 8, pp. 1644–1650, Aug. 2013.
 I. E. Wachs, Y. Chen, J.-M. Jehng, L. E. Briand, and T. Tanaka, “Molecular structure and reactivity of the Group V metal oxides,” Catal. Today, vol. 78, no. 1–4, pp. 13–24, Feb. 2003.
 S. Clima et al., “Dielectric Response of Ta2O5, NbTaO5 and Nb2O5 from First-Principles Investigations,” in ECS Transactions, 2009, vol. 19, pp. 729–737.
 D.-X. Zhang et al., “Thickness-dependence of optical constants for Ta2O5 ultrathin films,” Appl. Phys. A, vol. 108, no. 4, pp. 975–979, Sep. 2012
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
The texts published in this magazine, as of June of the year 2018, are under a Creative Commons License "Recognition-Non-Commercial-Share Equal" that allows others: