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arXiv · 2004.02572

Effect of Nd and Rh substitution on the spin dynamics of Kondo insulator CeFe2Al10

P. A. Alekseev·J. -M. Mignot·D. T. Adroja·V. N. Lazukov·H. Tanida·Y. Muro·M. Sera·T. Takabatake·P. Steffens·S. Rols
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Abstract

The dynamic magnetic properties of the Kondo-insulator state in CeFe2Al10 (spin gap, resonance mode) have been investigated using polarized neutrons on a single crystal of pure CeFe2Al10. The results indicate that the magnetic excitations are polarized mainly along the orthorhombic a axis and their dispersion along the orthorhombic c direction could be determined. Polycrystalline samples of Nd- and Rh-doped CeFe2Al0 were also studied by the time-of-flight technique, with the aim of finding out how the low-energy magnetic excitation spectra change upon isoelectronic substitution of the rare-earth (Nd) on the magnetic Ce site or electron doping (Rh) on the transition-element Fe sublattice. The introduction of magnetic Nd impurities strongly modifies the spin gap in the Ce dynamic magnetic response and causes the appearance of a quasielastic signal. The crystal-field excitations of Nd, studied in both LaFe2Al10 and CeFe2Al10, also reveal a significant influence of f-electron hybridization (largest in the case of Ce) on the crystal-field potential. As a function of the Rh concentration, a gradual change is observed from a Kondo-insulator to a metallic Kondo-lattice response, likely reflecting the decrease in the hybridization energy.

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P. A. Alekseev, J. -M. Mignot, D. T. Adroja, V. N. Lazukov, H. Tanida, Y. Muro, M. Sera, T. Takabatake, P. Steffens, S. Rols. 2020-04-06. Effect of Nd and Rh substitution on the spin dynamics of Kondo insulator CeFe2Al10. https://doi.org/10.1103/physrevb.102.024438

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