Energy scales of Lu(1-x)Yb(x)Rh2Si2 by means of thermopower investigations

TL;DR

This study investigates the thermopower and resistivity of Lu(1-x)Yb(x)Rh2Si2 across various temperatures, revealing how the Kondo effect and crystal electric field splitting evolve with composition, and estimating the Kondo temperature for YbRh2Si2.

Contribution

It provides new insights into the energy scales of the Kondo effect and crystal electric field splitting in Lu(1-x)Yb(x)Rh2Si2 through thermopower and resistivity measurements.

Findings

Thermopower changes from two minima to a single minimum as Yb content increases.

Low-temperature extrema are linked to the Kondo scale lowering with decreasing x.

Estimated Kondo temperature for YbRh2Si2 is approximately 29 K.

Abstract

We present the thermopower S(T) and the resistivity rho(T) of Lu(1-x)Yb(x)Rh2Si2 in the temperature range 3 K < T < 300 K. S(T) is found to change from two minima for dilute systems (x < 0.5) to a single large minimum in pure YbRh2Si2. A similar behavior has also been found for the magnetic contribution to the resistivity rho_mag(T). The appearance of the low-T extrema in S(T) and rho_mag(T) is attributed to the lowering of the Kondo scale with decreasing x. The evolution of the characteristic energy scales for both the Kondo effect and the crystal electric field splitting are deduced. An extrapolation allows to estimate the Kondo temperature of YbRh2Si2 to 29 K.