Magnetic and transport properties of CePt3Ge Kondo lattice in crystalline and sub-micron state
Résumé
We have studied a ternary phase of the CePt3 +/- xGe composition, with the maximum values of x = 0.2. A series of samples was prepared by arc melting, Czochralski method and splat cooling, and characterized by scanning electron microscopy and X-ray diffraction. The arc-melted samples are well-crystalline and single-phase with slightly varying stoichiometry close to the nominal CePt3Ge, while the splat-cooled samples form an amorphous or a nanocrystalline constitution of the similar to CePt3Ge composition. Detailed measurements of magnetization, specific heat and electrical resistivity were performed in the temperature range 0.40-300 K, and magnetic fields up to 9 T. In addition, a delicate neutron diffraction experiment down to 70 mK was done, which excluded long-range magnetic order in the CePt3Ge compound. The specific heat data were tested to anisotropic Kondo model, and the resistivity behavior has been treated by means of electron localization effects. The experiments evidenced that the CePt3Ge compound can be considered as a Kondo lattice with low-temperature magnetic correlations, and the size effect seems to have minor role in control of the Kondo scattering phenomena in this compound.