ИСТИНА

The novel cerium ternaries, Ce2IrGe3 and CeIrGe2, were studied by means of x-ray diffraction, magnetization, specific heat and electrical resistivity measurements, performed in wide ranges of temperature and external magnetic fields. Ce2IrGe3 was found to crystallize with slightly disordered hexagonal structure of the Ce2CoSi3 type, which is a derivative of the AlB2 prototype. In turn, CeIrGe2 was established to adopt the orthorhombic CeNiSi2 type unit cell, which can be described as packing of two kinds of slabs, corresponding to the AlB2 type and one half of the BaAl4 type blocks. While CeIrGe2 was characterized as a Kondo lattice that orders antiferromagnetically at TN = 4 K, Ce2IrGe3 was found to exhibit a ferromagnetic-like ordering below TC = 4 K, accompanied with several features typical for metallic spin glasses. Based on the thermodynamic and electrical transport data, the latter germanide was also described as a strongly correlated electron system.