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)

• 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

• 1. . J. Prchal, H. Kitazawa, T. Furubayashi, P. Javorský, K. Koyama, V. Sechovský, Physica B 378-380, 1102 (2006)
• 2. F. Merlo, S. Cirafici, F. Canepa, J. Alloys Comp. 266, 22 (1998)
• 3. A. Dönni, H. Kitazawa, P. Fischer, F. Fauth, J. Alloys Comp. 289, 11 (1999)
• 4. E. Talik, M. Skutecka, J. Kusz, H. Böhm, J. Jarosz, T. Mydlarz, A. Winiarski, J. Alloys Comp. 325, 42 (2001)
• 5. J. Prchal, P. Javorský, V. Sechovský, M. Dopita, O. Isnard, K. Jurek, J. Magn. Magn. Mater. 283, 34 (2004)
• 6. J. Prchal, P. Javorský, S. Daniš, K. Jurek, J. Dlouhý, Czech. J. Phys. , 54 (20 suppl. D, 315) 04
• 7. J. Rodriguez-Carvajal, Physica B 192, 55 (1993)
• 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