Magnetic properties and thermal expansion of YbGaxGe2−x (0.9≤x≤1.5)

The composition dependence of the Yb valence and of the thermal expansion have been studied in the YbGaxGe2−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.