Influence of the mixed-valences state on the magnetic excitation spectrum of SmB{sub 6}-based compounds
- Kurchatov Institute, Moscow (Russian Federation); and others
A series of experimental studies of the dynamical magnetic response of Sm in SmB{sub 6}-based mixed-valence (MV) systems has been carried out by inelastic neutron scattering on poly- and single-crystalline, double-isotopic ({sup 154}Sm, {sup 11}B), samples. In addition to two strongly damped high-energy peaks associated with the inter-multiplet transitions of Sm{sup 2+} and Sm{sup 3+}, pure SmB{sub 6} exhibits a very specific low-energy excitation at 14 meV. These features can be ascribed to the formation of the MV ground state. To study the effect of a variation of the average valence {nu} on the magnetic excitation spectra, solid solutions have been studied in which 2+ or 3+ ions are substituted for Sm. The intensities of the inter-multiplet excitations change are observed in the position of the low-energy peak and in the Q and T dependences of its intensity. Further information concerning the energy, anisotropy, and Q and T dependences of the low-energy excitation was obtained from triple-axis experiments on single crystals of Sm{sub 1-x}La{sub x}B{sub 6} (x = 0.10, 0.22) at ambient pressure and SmB{sub 6} at P = 0.5 GPa. The transformations observed in the low-energy part of the spectra suggest a relation between the average valence and the degree of delocalization (or hybridization strength) for the {open_quotes}loosely bound{close_quotes} {line_integral}-electron state formed around the Sm ion, which is a characteristic feature of the MV ground state.
- OSTI ID:
- 569550
- Journal Information:
- Journal of Solid State Chemistry, Vol. 133, Issue 1; Other Information: PBD: Oct 1997
- Country of Publication:
- United States
- Language:
- English
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