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Tunable Thermal Expansion Behavior in the Intermetallic YbGaGe

F. R. Drymiotis·Y. Lee·G. Lawes·J. C. Lashley·T. Kimura·S. M. Shapiro·A. Migliori·V. Correa·R. A. Fisher
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Abstract

We investigate the effects of carbon and boron doping on the thermal expansion in the hexagonal (P63/mmc) intermetallic YbGaGe. X-ray powder diffraction was used to measure the lattice constants on pure and doped (C or B at nominal levels of 0.5 %) samples from T~10 K to T~300 K. Also measured were resistivity, specific-heat, and magnetic susceptibility. While the pure YbGaGe samples exhibit positive thermal volume expansion, (V300K-V10K)/V300K = 0.94%, the volume expansion in the lightly C and B-doped samples, contract and tend towards zero volume expansion. Such a strong response with such light doping suggests that the underlying mechanism for the reported zero volume expansion is substitutional disorder, and not the previously proposed valence fluctuations.

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F. R. Drymiotis, Y. Lee, G. Lawes, J. C. Lashley, T. Kimura, S. M. Shapiro, A. Migliori, V. Correa, R. A. Fisher. 2004-10-19. Tunable Thermal Expansion Behavior in the Intermetallic YbGaGe. https://doi.org/10.1103/physrevb.71.174304

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