Anisotropic magnetic behavior of single crystalline CeGe

We report the anisotropic magnetic properties of a Czochralski grown single crystal of CeGe, which crystallizes in the orthorhombic structure with the space group Pnma ({\#}63). The compound orders antiferromagnetically at TN = 10.9 K, in agreement with the value reported previously on a polycrystalline sample. A metamagnetic transition at $\sim $ 6.5 T followed by saturation at higher fields is observed along [010], the easy axis of magnetization. The heat capacity data confirm the bulk nature of magnetic ordering with a peak of nearly 13 J/mol K at 10.9 K. The peak decreases in height and shifts to lower temperatures in applied magnetic field, consistent with the antiferromagnetic ordering of Ce ions. Subtraction of phonon heat capacity, as measured for LaGe, reveals a broad hump around 30 K, suggesting the existence of low lying crystal electric field levels, which is well reproduced by two doublets located at 45 and 152 K, respectively. The electrical resistivity shows normal metallic behavior indicating the absence of Kondo interaction. At TN the resistivity measured along the three principal directions shows an upturn which is tentatively attributed to the gaps opened in the antiferromagnetic state. A magnetic phase diagram has been constructed based on the magnetization data.