Europhys. Lett.
Volume 69, Number 1, January 2005
Page(s) 88 - 94
Section Condensed matter: structure, mechanical and thermal properties
Published online 08 December 2004
Europhys. Lett., 69 (1), pp. 88-94 (2005)
DOI: 10.1209/epl/i2004-10302-7

Bulk properties of $\chem{YbGaGe}$: A question of zero thermal expansion

Kwang-hyun Jang1, Wan Young Song1, 2, J.-G. Park1, 2, H. C. Kim3, A. Lindbaum4, H. Müller4 and E. Bauer4

1  Department of Physics and Institute of Basic Science, Sungkyunkwan University Suwon 440-746, Korea
2  Center for Strongly Correlated Materials Research, Seoul National University Seoul 151-742, Korea
3  Material Science Laboratory, Korea Basic Science Institute - Daejon 305-333, Korea
4  Institute of Solid State Physics, Vienna University of Technology A-1040 Wien, Austria

received 28 January 2004; accepted in final form 26 October 2004
published online 8 December 2004

Despite the recent report of zero thermal expansion in $\chem{YbGaGe}$, our extensive studies of the physical properties of pure $\chem{YbGaGe}$ failed to find anomalous behavior of the thermal expansion of both X-ray and dilatometry measurements. Instead, the temperature dependence of the lattice constants can be simply explained in terms of the Debye model with the cutoff frequency of 226 $\un{K}$, which was estimated from heat capacity measurement. Additionally, susceptibility measurements have not revealed any sign of a change of the $\chem{Yb}$ valency from 2 to 700 $\un{K}$, but magnetic correlations develop at low temperatures. Important findings of further interest are that $\chem{YbGaGe}$ has very strong low-lying optic phonons, 1.7 oscillator strength with an energy of 80 $\un{K}$, and shows strong increase of Grüneisen parameter below 20 $\un{K}$.

65.40.De - Thermal expansion; thermomechanical effects.
61.10.Nz - X-ray diffraction.
65.40.Ba - Heat capacity.

© EDP Sciences 2005