Tsuneo Miura

Thermal, electrical and magnetic properties of the ferromagnetic dense Kondo system CeSix

Single crystals of the ferromagnetic dense Kondo system CeSi x were grown, and the specific heat, the electrical resistivity and the magnetic susceptibility were measured. Electrical resistivity measurements clearly show the typical Kondo behavior, which unambiguously tells that CeSi x is a ferromagnetic dense Kondo system. The appreciable anisotropy of the magnetic susceptibility is analyzed with the crystalline field effect and a conjecture is made that the ground doublet is a \(\varGamma_{7}\)-like doublet.

Multiple Phase Transitions of Single Crystalline CeGa2

A single crystalline CeGa 2 was obtained by floating-zone technique. Electrical resistivity data showed no Kondo like behavior. Specific heat measurements revealed successive phase transitions at around 10 K. Magnetic measurements showed that these are related with various magnetic states of CeGa 2 . The lowest temperature phase was ferromagnetic and the magnetic phase diagram with respect to temperature and magnetic field was proposed.

Magnetic Excitations of a Ferromagnetic Dense Kondo System CeSi1.8

We have studied the low energy magnetic excitations of the ferromagnetic dense Kondo system CeSix by neutron inelastic scattering measurements performed on a single crystal of CeSi1.8 (TC = 13.4 K). A spin-wave-like inelastic response was observed below TC over the Brillouin zone. The line widths of the excitations are, however, abnormally large. These features are substantially unchanged below TC. The present results suggest that the excited state of the ferromagnetic CeSi1.8 is unstable at low temperatures because of the Kondo effect.

Single Crystals of CuxMo6Se8: Growth, Compositional Inhomogeneity and Superconducting Properties

Single crystals of Chevrel-type compounds CuxMo6Se8 (0≤x≤2.4) have been grown by the Bridgman method under a He pressure of 50~100 atm, The content of copper x is observed to be gradually enriched as the crystal growth proceeded. The superconducting transition temperature Tc is determined as a function of x. The results are summarized into three regions; 6.0\lesssimTc\lesssim6.5 for 0≤x\lesssim0.7, 6.0\lesssimTc\lesssim5.0 for 0.7 2.0. The transition temperature width, ΔTc, increases with increasing x. The results of XPS indicate that no marked change occurrs with variation of x. The oxidation from Cu1+ to Cu2+ is observed by XPS on the surface of the pulverized crystals.