  The composition dependence of the Yb valence and of the thermal expansion
have been studied in the YbGa$_x$Ge$_{2-x}$ system. X-ray diffraction reveals
that single-phased samples isostructural to YbGaGe are obtained in the range of
0.9 <= x <= 1.5. The magnetic susceptibility shows that the systems are almost
nonmagnetic below room temperature, indicating a stable Yb2+ state for the x
range 0.9 <= x <= 1.5. The lattice constants as well as the lattice volume of
these systems are found to decrease monotonically with decreasing temperature,
suggesting the absence of zero thermal-expansion previously reported for
YbGaGe.
