MAGNETIC EXCITATIONS AND VARIATION OF VALENCE IN SMB6-BASED SYSTEMS

In order to study the effect of a variation of the average valence v o n the magnetic excitation spectra, a series of measurements of the dyn amical magnetic response of Sm in SmB6-based mixed-valence (MV) system s has been carried out by inelastic neutron scattering on poly- and si ngle-crystalline, double-isotopic(Sm-154, B-11), samples. Solid soluti ons have been studied in which 2(+) or 3(+) ions are substituted for S m. Systematic changes are observed in the position of the low-energy p eak, and in the Q- and T-dependence of its intensity. The intensities of the inter-multiplet excitations change roughly in accordance with t he variation of v. Further Information concerning the energy, anisotro py and the Q- and T-dependences of the low-energy excitation was obtai ned from triple-axis experiments on single crystals of Sm1-xLaxB6 and SmB6 under the 0.5 GPa pressure.