Magnetic properties and spin kinetics of a heavy-fermion Kondo lattice

Abstract

A review of peculiarities of magnetic properties and spin kinetics of a heavy-fermion Kondo lattice revealed by electron spin resonance (ESR) experiments and their theoretical analysis is given. Among the issues discussed in some detail are the renormalization of spin kinetics coefficients due to the Kondo effect, formation of the collective spin modes of the Kondo ions and wide-band conduction electrons, unexpected behavior of ESR parameters as functions of temperature and magnetic fields. Special attention is focused on the possible role of the Kondo effect for the ESR signal existence at low temperatures.

Spin Dynamics of (Sc $$_{1-x}$$ 1 - x Lu $$_{x}$$

“…This indicates that disorder, introduced by Lu substitution, is also an important ingredient for the relaxation mechanism of the observed resonance. This was similarly discussed for the ESR in the La-substituted Kondo lattice system YbRh Si [ 16 ], where the resonance is understood to originate from the formation of collective spin modes of Kondo ions and conduction electrons [ 18 ].…”

Detection of Two Phenomena Opposite to the Expected Ones

“…We consider the energy band symmetric relative to the Fermi level, the electron energy ξ k measured from the latter in the range (−W, W). To simplify calculations, it is reasonable to use the following case: k B T W and S = 1/2, see [20]. Taking into account the second-order contribution δH 0 ex , one can obtain the following expression for the isotropic symmetry:…”

“…For a detailed comparison of the theory with experimental results, it is necessary to take into account additional interactions of the magnetic impurities and the conduction electrons like spin-phonon, magnetic dipole-dipole, and RKKY interactions and also an inhomogeneity of the static external magnetic field. Some results of these investigations can be found in the review [20].…”