Please use this identifier to cite or link to this item: http://hdl.handle.net/10995/102467
Title: Correlation effects and phonon modes softening with doping in Ba 1-xKxBiO3
Authors: Korotin, D. M.
Novoselov, D.
Anisimov, V. I.
Issue Date: 2014
Publisher: Institute of Physics Publishing
Citation: Korotin D. M. Correlation effects and phonon modes softening with doping in Ba 1-xKxBiO3 / D. M. Korotin, D. Novoselov, V. I. Anisimov. — DOI 10.1088/0953-8984/26/19/195602 // Journal of Physics Condensed Matter. — 2014. — Vol. 26. — Iss. 19. — 195602.
Abstract: The monoclinic crystal structure of the undoped BaBiO3 can be described as a cubic perovskite which is distorted by the frozen breathing and tilting phonon modes of the BiO6 octahedra. The phonon mode softening is experimentally observed (Braden et al 1996 Europhys. Lett. 34 531) in Ba1-xKxBiO3 through potassium doping followed by a transition into an ideal cubic perovskite structure at x = 0.37, close to the emergence of superconductivity. In our previous paper (Korotin et al 2012 J. Phys.: Condens. Matter 24 415603) we demonstrated that it is necessary to take into account correlation effects using the DFT+U method in Wannier functions as a basis to obtain a good agreement between the calculated and experimental values of crystal structure distortion and the energy gap in BaBiO3. In the present work, using the same method, we calculated the breathing mode phonon frequencies as a function of the potassium doping level in Ba1-xKxBiO3. The obtained frequencies are in good agreement with experimental values and the breathing mode softening with doping is reproduced, contrary to calculations made without consideration of correlation effects. We show that the cubic crystal structure becomes stable at x = 0.30 in agreement with the experimental transition to cubic perovskite at x = 0.37. The possible connections between the correlation effects, phonon mode softening and superconductivity in Ba1-xKxBiO3 are discussed. © 2014 IOP Publishing Ltd.
Keywords: CORRELATED ELECTRONS
ELECTRON-PHONON INTERACTION
WANNIER FUNCTIONS
CORRELATION DETECTORS
ELECTRON-PHONON INTERACTIONS
PEROVSKITE
PHONONS
POTASSIUM
CORRELATED ELECTRONS
CORRELATION EFFECT
CUBIC CRYSTAL STRUCTURES
EXPERIMENTAL VALUES
MONOCLINIC CRYSTAL STRUCTURE
PHONON FREQUENCIES
STRUCTURE DISTORTIONS
WANNIER FUNCTIONS
CRYSTAL STRUCTURE
URI: http://hdl.handle.net/10995/102467
Access: info:eu-repo/semantics/openAccess
SCOPUS ID: 84899565473
PURE ID: 374166
e273de85-f092-4586-96e8-ae8c01a79769
ISSN: 9538984
DOI: 10.1088/0953-8984/26/19/195602
Appears in Collections:Научные публикации, проиндексированные в SCOPUS и WoS CC

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