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Dopants and dopant–vacancy complexes in tetragonal lead titanate: A systematic first principles study

Erhart, Paul and Albe, Karsten (2015):
Dopants and dopant–vacancy complexes in tetragonal lead titanate: A systematic first principles study.
In: Computational Materials Science, Elsevier Science Publishing, pp. 224-230, 103, ISSN 09270256,
[Online-Edition: http://dx.doi.org/10.1016/j.commatsci.2015.02.029],
[Article]

Abstract

A systematic investigation of dopants in tetragonal lead titanate is presented by screening elements from the third period including K, Ca and all 3d3d transition metals. Formation energies and equilibrium transition states are determined by means of density functional theory calculations for both cation sites in the perovskite lattice, which allows us to discriminate between donor and acceptor type behavior. The stability of defect dipoles is determined by calculating the binding energy of transition metal-vacancy complexes. The results reveal that the tendency to substitute the Pb-site rather than the Ti-site monotonically increases going from Ti to Zn. The transition from Ti to Pb substitution depends both on the chemical equilibrium conditions and the position of the Fermi energy. This is most evident for Sc and Zn dopants that in principle can occupy both Pb- and Ti-sites depending on preparation conditions. Except for V all acceptor dopants form defect complexes with oxygen vacancies and thus can form defect dipoles causing hardening as well as aging effects. Defect dipoles involving Pb substitution and oxygen vacancies are found to be unfavorable for all dopants considered here.

Item Type: Article
Erschienen: 2015
Creators: Erhart, Paul and Albe, Karsten
Title: Dopants and dopant–vacancy complexes in tetragonal lead titanate: A systematic first principles study
Language: English
Abstract:

A systematic investigation of dopants in tetragonal lead titanate is presented by screening elements from the third period including K, Ca and all 3d3d transition metals. Formation energies and equilibrium transition states are determined by means of density functional theory calculations for both cation sites in the perovskite lattice, which allows us to discriminate between donor and acceptor type behavior. The stability of defect dipoles is determined by calculating the binding energy of transition metal-vacancy complexes. The results reveal that the tendency to substitute the Pb-site rather than the Ti-site monotonically increases going from Ti to Zn. The transition from Ti to Pb substitution depends both on the chemical equilibrium conditions and the position of the Fermi energy. This is most evident for Sc and Zn dopants that in principle can occupy both Pb- and Ti-sites depending on preparation conditions. Except for V all acceptor dopants form defect complexes with oxygen vacancies and thus can form defect dipoles causing hardening as well as aging effects. Defect dipoles involving Pb substitution and oxygen vacancies are found to be unfavorable for all dopants considered here.

Journal or Publication Title: Computational Materials Science
Volume: 103
Publisher: Elsevier Science Publishing
Uncontrolled Keywords: Degradation, Electrical and mechanical loading, Defects, Doping, PZT
Divisions: 11 Department of Materials and Earth Sciences
11 Department of Materials and Earth Sciences > Material Science
11 Department of Materials and Earth Sciences > Material Science > Materials Modelling
Zentrale Einrichtungen
DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres > CRC 595: Electrical fatigue
DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres > CRC 595: Electrical fatigue > C - Modelling > Subproject C1: Quantum mechanical computer simulations for electron and defect structure of oxides
DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres > CRC 595: Electrical fatigue > C - Modelling
DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres
DFG-Collaborative Research Centres (incl. Transregio)
Date Deposited: 23 Apr 2015 11:25
Official URL: http://dx.doi.org/10.1016/j.commatsci.2015.02.029
Identification Number: doi:10.1016/j.commatsci.2015.02.029
Funders: This work has been partly supported by SFB 595 “Electrical fatigue in functional materials”., P.E. acknowledges funding from the “Areas of Advanced Materials Science” at Chalmers, the Swedish Research Council in the form of a Young Researcher Grant and the European Research Council in the form of a Marie Curie Career Integration Grant.
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