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Title: High-resolution neutron powder diffraction study on the phase transitions in BaPbO{sub 3}

Abstract

Phase transitions that occurred in perovskite BaPbO{sub 3} have been investigated using high-resolution time-of-flight neutron powder diffraction. The structure at room temperature is orthorhombic (space group Imma), which is derived from the cubic aristotype by tilting the PbO{sub 6} octahedra around the two-fold axis (tilt system a {sup 0} b {sup -} b {sup -}). The orthorhombic structure shows anisotropic line broadening attributed to the presence of micro twins. At above about 573 K, BaPbO{sub 3} undergoes a discontinuous phase transition to a tetragonal structure (space group I4/mcm) with the tilting of the PbO{sub 6} octahedra being about the four-fold axis of the cubic aristotype (tilt system a {sup 0} a {sup 0} c {sup -}). With further increasing the temperature, BaPbO{sub 3} experiences a continuous phase transition to a simple cubic structure (space group Pm3-barm) at above about 673 K. The later phase transition is characterised by a critical exponent of {beta}=0.36, depicted by the three-dimensional Heisenberg universality class. The earlier reported Imma{sup {yields}}I2/m phase transition above room temperature has not been observed. - Graphical abstract: Temperature dependence of the octahedral tilting angles in BaPbO{sub 3}. The continuous line in tetragonal phase region is the fit to the expression:more » {phi}=A(T {sub c}-T) {sup {beta}} with the fitted values of T {sub c}=658(1) K, {beta}=0.36(2) and A=1.1(1). The shaded area indicates the possible two-phase region.« less

Authors:
 [1];  [2];  [3];  [4]
  1. Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden (Netherlands), E-mail: w.fu@chem.leidenuniv.nl
  2. NWO-Physics, ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX (United Kingdom)
  3. ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX (United Kingdom)
  4. Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden (Netherlands)
Publication Date:
OSTI Identifier:
21015809
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 180; Journal Issue: 5; Other Information: DOI: 10.1016/j.jssc.2007.03.009; PII: S0022-4596(07)00106-5; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ANISOTROPY; CUBIC LATTICES; LINE BROADENING; NEUTRON DIFFRACTION; ORTHORHOMBIC LATTICES; PEROVSKITE; PHASE TRANSFORMATIONS; SPACE GROUPS; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0273-0400 K; TEMPERATURE RANGE 0400-1000 K; TETRAGONAL LATTICES; TIME-OF-FLIGHT METHOD

Citation Formats

Fu, W.T., Visser, D., Knight, K.S., and IJdo, D.J.W. High-resolution neutron powder diffraction study on the phase transitions in BaPbO{sub 3}. United States: N. p., 2007. Web. doi:10.1016/j.jssc.2007.03.009.
Fu, W.T., Visser, D., Knight, K.S., & IJdo, D.J.W. High-resolution neutron powder diffraction study on the phase transitions in BaPbO{sub 3}. United States. doi:10.1016/j.jssc.2007.03.009.
Fu, W.T., Visser, D., Knight, K.S., and IJdo, D.J.W. Tue . "High-resolution neutron powder diffraction study on the phase transitions in BaPbO{sub 3}". United States. doi:10.1016/j.jssc.2007.03.009.
@article{osti_21015809,
title = {High-resolution neutron powder diffraction study on the phase transitions in BaPbO{sub 3}},
author = {Fu, W.T. and Visser, D. and Knight, K.S. and IJdo, D.J.W.},
abstractNote = {Phase transitions that occurred in perovskite BaPbO{sub 3} have been investigated using high-resolution time-of-flight neutron powder diffraction. The structure at room temperature is orthorhombic (space group Imma), which is derived from the cubic aristotype by tilting the PbO{sub 6} octahedra around the two-fold axis (tilt system a {sup 0} b {sup -} b {sup -}). The orthorhombic structure shows anisotropic line broadening attributed to the presence of micro twins. At above about 573 K, BaPbO{sub 3} undergoes a discontinuous phase transition to a tetragonal structure (space group I4/mcm) with the tilting of the PbO{sub 6} octahedra being about the four-fold axis of the cubic aristotype (tilt system a {sup 0} a {sup 0} c {sup -}). With further increasing the temperature, BaPbO{sub 3} experiences a continuous phase transition to a simple cubic structure (space group Pm3-barm) at above about 673 K. The later phase transition is characterised by a critical exponent of {beta}=0.36, depicted by the three-dimensional Heisenberg universality class. The earlier reported Imma{sup {yields}}I2/m phase transition above room temperature has not been observed. - Graphical abstract: Temperature dependence of the octahedral tilting angles in BaPbO{sub 3}. The continuous line in tetragonal phase region is the fit to the expression: {phi}=A(T {sub c}-T) {sup {beta}} with the fitted values of T {sub c}=658(1) K, {beta}=0.36(2) and A=1.1(1). The shaded area indicates the possible two-phase region.},
doi = {10.1016/j.jssc.2007.03.009},
journal = {Journal of Solid State Chemistry},
number = 5,
volume = 180,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}