Density Functional Calculations of the Electronic Band Structure and Optical Properties of KCaF3

Year 2011, Volume: 24 Issue: 4, 671 - 677, 10.01.2011

Bahattin Erdinc

Abstract

The electronic band structure and optical properties of cubic KCaF₃ are studied using the density functional theory. The calculated band structure of cubic KCaF₃ shows an indirect band gap with two values of 5.95 eV and 5.94 eV at the M ® G and G ® R lines of Brillouin zone, respectively. The structural optimization has been performed using the generalized gradient approximation (GGA). The calculated structure optimization of KCaF₃ has been compared with experimental results. Good agreement between theoretical and experimental results was observed. Moreover, some optical constants such as energy-loss functions for volume and surface, coefficients of extinction, reflectivity and absorption, refractive index and effective number of valence electrons per unit cell participating in the inter-band transitions and the linear photon-energy-dependent dielectric functions have been calculated.

 

PACS number: 71.15.Mb; 74.25.Jb; 74.25.Gz

Keywords: Density functional theory, Electronic structure; Optical properties

 

Keywords

Density functional theory, Electronic structure; Optical properties

References

• Demetriou, D. Z., Catlow, C. R. A., Chadwick, A. V., Mclntyre, G. J. and Abrahams, I., “The Anion Disorder in the Perovskite Fluoride KCaF3”, Solid State Ionics, 176: 1571 - 1575 (2005).
• Daniel, P. H., Rousseau, M., and Toulouse, J., “Raman Scattering Study of Potassium Calcium Fluoride KCaF3”, Phys. Status. Solidi. (b), 203: 327 - 335 (1997).
• Flocken J. W., Guenther R. A., Hardy J. R., and Boyer, L. L., “A Priori Predictions of Phase Transitions in KCaF3 and RbCaF3: Existence of a New Ground State”, Phys. Review Lett, 56: 1738 - 1741 (1986).
• Chornodolskyy, Y., Syrotyuk, S., Stryganyuk, G., Voloshinovskii, A. and Rodnyi P., “Electronic Energy Structure and Core-Valence Luminescence of ABX3” (A = K, Rb, Cs; B = Ca; X = F), Journal of Physical Studies, 4: 421 - 426 (2007).
• Watson, G. W., Parker, S. C. and Wall, A., J., “Molecular Dynamics Simulation in Fluoride Perovskites”, J. Phys. Condens. Matter, 42: 2097-2108 (1992).
• Rousseauy, M., Daniely, Ph. and Hennion, B., “The dynamic signature of highly anisotropic correlation near the phase transition in KCaF3”, J. Phys. Condens. Matter, 9: 8963 - 8971 (1997).
• Troullier, N., Martins, J.L., “Efficient Pseudopotentials for Plane-wave Calculations”, Phys. Rev. B, 43: 1993-2006 (1990).
• J Perdew, J. P., Burke, K., Ernzerhof, M., “Generalized Gradient Approximation Made Simple”, Phys. Rev. Lett., 77: 3865-3868 (1996).
• Kohn, W., Sham, L.J., “Self-Consistent Equations Including Exchange and Correlation Effects”, Phys. Rev., 140: A1133-A1138 (1965).
• Payne, M.C., Teter, M. P., Allan, D.C., Arias, T.A., Joannopoulos, J.D., “Iterative Minimization Techniques for Ab initio Total-energy Calculations: Molecular Dynamics and Conjugate Gradients”, Rev. Mod. Phys., 64: 1045-1097 (1992).
• Gonze, X., Beuken, J.M., Caracas, R., Detraux, F., Fuchs, M., Rignanese, G. M., Sindic, L., Verstrate, M., Zerah, G., Jollet, F., Torrent, M., Roy, A., Mikami, M., Ghosez, P., Raty, J. Y., and Allan, D. C., “First-principle Computation of Material Properties: the ABINIT Software Project”, Comput. Mater. Sci., 25: 478-492 (2002).
• Monkhorst, H.J., Pack, J. D., “Special Points for Brillouin-zone Integrations”, Phys. Rev. B, 13: 5188-5192 (1976).
• Hughes, J.L.P., Sipe, J.E., “Calculation of Secondorder Optical Response in Semiconductors”, Phys. Rev. B, 53:10751-10763 (1996).
• K. S. Aleksaudrov, A. T. Anistratov, B. V. Beznosikov and N. B. Fedoseeva, Science Norosibirsk (in Russian), (1981).
• Philipp, H.R., Ehrenreich, H., “Optical Properties of Semiconductors”, Phys. Rev., 129: 1550-1560 (1963).