High-Pressure Synthesis and Properties of a Cerium Germanide CeGe3 with the Cubic Cu3Au Type Structure

A new cerium germanide, CeGe3 was prepared by the reaction of a stoichiometric mixture of CeGe2 and Ge under a pressure of 5 GPa at 1600 °C. It crystallized in a cubic unit cell with a = 4.354 (4) (angstrom), and was isotypic with CeSn3 and CePb3 having the Cu3Au structure. It showed a Curie–Weiss paramagnetic behavior from room temperature to 20 K with a Curie constant C of 0.0495 emu mol^-1·K. The effective magnetic moment of 0.63 (mu)B, which was much smaller than the theoretical values of 2.54 (mu)B for Ce3+ (4f1) ions, was observed. This compound showed a metallic behavior with the resistivity of 130 and 7 (mu)(omega)·cm at room temperature and 2 K, respectively.