Yb-Based Kondo Lattices: Insight from 170 Yb Mössbauer, Positive Muon and γ–γ Perturbed Angular Correlations Spectroscopies

Abstract

The usefulness of local hyperfine techniques in the investigation of the physical properties of Kondo lattices is illustrated through three examples. First, we show how Mossbauer spectroscopy on 170Yb down to very low temperature (0.025 K) provides evidence for the existence of an incommensurate modulated magnetic structure close to T=0 in YbPtAl; a modulated structure at T=0 is in principle forbidden for Kramers ions, but it is made possible in YbPtAl due to the presence of the Kondo coupling. Second, we present a μSR study of the Kondo insulator YbB12, and we evidence the persistence of fluctuations of very small correlated Yb moments close to T=0. Third, we report on a study by Perturbed Angular Correlation spectroscopy on the isotope 172Yb of the Kondo lattice Yb2Co3Ga9, which is characterised by a high Kondo temperature (T0≃260 K). Our aim was to compare, on a large temperature range, the thermal variations of the 4f quadrupole moment and of the magnetic susceptibility, to check whether the scaling property predicted by theory could be observed.