"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
Physical Review B
Vol.71, No.17, pp.17430, 2005.05
We investigate the effects of carbon and boron doping on the thermal expansion of the hexagonal 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 . Also measured were resistivity, specific heat, and magnetic susceptibility. While the pure YbGaGe samples exhibit positive thermal volume expansion, , the volume expansion in the lightly C- or B-doped samples changes slope and tends toward zero-volume expansion. Such a strong response to light doping suggests that the underlying mechanism for the reported zero-volume expansion is substitutional disorder, and not the previously proposed valence fluctuations.