Computer modelling of KTN solid solutions

G. Borstel; R. I. Eglitis; E. A. Kotomin

Computer modelling of KTN solid solutions

G. Borstel^*
, R. I. Eglitis
, E. A. Kotomin

^*Corresponding author for this work

Osnabrück University

Research output: Contribution to conference › Paper › peer-review

Abstract

The results of quantum chemical modelling of perovskite solid solutions KNb_xTa_1-xO₃ are presented and compared with recent full-potential LMTO calculations. We show that Nb atoms in KTaO₃ reveal off-center displacements along both the [100] and [111] axes at as low concentrations as x = 0.125, which is in much better agreement with XAFS experiments than full potential LMTO calculations. The analysis of the optimized atomic and electronic structure clearly demonstrates that several nearest Nb impurities in KTaO₃ are able for self-ordering and reveal a cooperative behaviour. This probably triggers the KTN ferroelectric phase transition. In contrast, Ta impurities in KNbO₃ reveal no self-ordering. The qualitatively different behaviour of Nb and Ta atoms could be caused by a small difference in their chemical bonding with other atoms, first of all oxygens.

Original language	English
Pages	671-674
Number of pages	4
Publication status	Published - 2000
Externally published	Yes
Event	12th IEEE International Symposium on Applications of Ferroelectrics - Honolulu, HI, United States Duration: 21 Jul 2000 → 2 Aug 2000

Conference

Conference	12th IEEE International Symposium on Applications of Ferroelectrics
Country/Territory	United States
City	Honolulu, HI
Period	21/07/00 → 2/08/00

Keywords

Ab initio and semi-empirical calculations
ABO perovskites
INDO
Phase transitions

Cite this

@conference{1553a16acdee41e48d50667e5a94e0fe,

title = "Computer modelling of KTN solid solutions",

abstract = "The results of quantum chemical modelling of perovskite solid solutions KNbxTa1-xO3 are presented and compared with recent full-potential LMTO calculations. We show that Nb atoms in KTaO3 reveal off-center displacements along both the [100] and [111] axes at as low concentrations as x = 0.125, which is in much better agreement with XAFS experiments than full potential LMTO calculations. The analysis of the optimized atomic and electronic structure clearly demonstrates that several nearest Nb impurities in KTaO3 are able for self-ordering and reveal a cooperative behaviour. This probably triggers the KTN ferroelectric phase transition. In contrast, Ta impurities in KNbO3 reveal no self-ordering. The qualitatively different behaviour of Nb and Ta atoms could be caused by a small difference in their chemical bonding with other atoms, first of all oxygens.",

keywords = "Ab initio and semi-empirical calculations, ABO perovskites, INDO, Phase transitions",

author = "G. Borstel and Eglitis, \{R. I.\} and Kotomin, \{E. A.\}",

year = "2000",

language = "English",

pages = "671--674",

note = "12th IEEE International Symposium on Applications of Ferroelectrics ; Conference date: 21-07-2000 Through 02-08-2000",

}

TY - CONF

T1 - Computer modelling of KTN solid solutions

AU - Borstel, G.

AU - Eglitis, R. I.

AU - Kotomin, E. A.

PY - 2000

Y1 - 2000

N2 - The results of quantum chemical modelling of perovskite solid solutions KNbxTa1-xO3 are presented and compared with recent full-potential LMTO calculations. We show that Nb atoms in KTaO3 reveal off-center displacements along both the [100] and [111] axes at as low concentrations as x = 0.125, which is in much better agreement with XAFS experiments than full potential LMTO calculations. The analysis of the optimized atomic and electronic structure clearly demonstrates that several nearest Nb impurities in KTaO3 are able for self-ordering and reveal a cooperative behaviour. This probably triggers the KTN ferroelectric phase transition. In contrast, Ta impurities in KNbO3 reveal no self-ordering. The qualitatively different behaviour of Nb and Ta atoms could be caused by a small difference in their chemical bonding with other atoms, first of all oxygens.

AB - The results of quantum chemical modelling of perovskite solid solutions KNbxTa1-xO3 are presented and compared with recent full-potential LMTO calculations. We show that Nb atoms in KTaO3 reveal off-center displacements along both the [100] and [111] axes at as low concentrations as x = 0.125, which is in much better agreement with XAFS experiments than full potential LMTO calculations. The analysis of the optimized atomic and electronic structure clearly demonstrates that several nearest Nb impurities in KTaO3 are able for self-ordering and reveal a cooperative behaviour. This probably triggers the KTN ferroelectric phase transition. In contrast, Ta impurities in KNbO3 reveal no self-ordering. The qualitatively different behaviour of Nb and Ta atoms could be caused by a small difference in their chemical bonding with other atoms, first of all oxygens.

KW - Ab initio and semi-empirical calculations

KW - ABO perovskites

KW - INDO

KW - Phase transitions

UR - https://www.scopus.com/pages/publications/0034474415

M3 - Paper

AN - SCOPUS:0034474415

SP - 671

EP - 674

T2 - 12th IEEE International Symposium on Applications of Ferroelectrics

Y2 - 21 July 2000 through 2 August 2000

ER -

Computer modelling of KTN solid solutions

Abstract

Conference

Keywords

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