Isostructural Transition in RTAl Compounds at High Temperatures

• Authors: J. Prchal , P. Javorský , F. de Boer , A. Moleman
• Languages of publication: EN

Abstracts

EN

Based on previously discovered forbidden values of the c/a ratio, we studied anomalies in the temperature evolution of the lattice parameters (a, c) of several hexagonal RTAl compounds at high temperatures (above room temperature). The compound ErNi_{0.45}Cu_{0.55}Al, that seemed to be impossible to be prepared in single-phase form, reaches the single-phase state at temperatures above 493 K (220°C). On the other hand, the compound TbNi_{0.7}Cu_{0.3}Al - that was expected to undergo a first-order structural phase transition at high temperatures - exhibits a second-order type transition when approaching the critical values of the c/a ratio. These results are in agreement with idea of a forbidden range of c/a values in these compounds.

Keywords

EN

61.50.Ks; 61.05.cp

Discipline

• 61.05.cp: X-ray diffraction
• 61.50.Ks: Crystallographic aspects of phase transformations; pressure effects(see also 81.30.Hd in materials science)

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 2008
• Volume: 113
• Issue: 1
• Pages: 335-338

Dates

published

2008-01

received

2007-07-09

Contributors

author

J. Prchal

• Charles University, Faculty of Mathematics and Physics, DCMP, Ke Karlovu 5, 121 16 Prague 2, Czech Republic

author

P. Javorský

• Charles University, Faculty of Mathematics and Physics, DCMP, Ke Karlovu 5, 121 16 Prague 2, Czech Republic

author

F. de Boer

• Universiteit van Amsterdam, Van der Waals-Zeeman Instituut, Valckenierstraat 65, 1018 XE Amsterdam, The Netherlands

author

A. Moleman

• Universiteit van Amsterdam, Van der Waals-Zeeman Instituut, Valckenierstraat 65, 1018 XE Amsterdam, The Netherlands

References

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• 8. G. Ehlers, Ph.D. Thesis, Berlin 1997
• 9. J. Prchal, H. Kitazawa, O. Suzuki, J. Alloys Comp. 437, 117 (2007)

Identifiers

DOI

10.12693/APhysPolA.113.335