Transport and thermodynamic properties of YbInNi4-xCux system

We report on specific heat and resistivity results on YbInNi4-xCux with 0 less than or equal to x less than or equal to 4. The magnetic resistivity for x less than or equal to 1 presents two temperature regions with a - In T dependence due to the crystal field (CF) and show that the splitting of the first excited state increases with the Cu concentration. The specific heat results are in agreement with resistivity and lead to the evaluation of crystal field splitting for the first and second excited states. The energy level scheme remains unaltered when Cu replaces Ni. The unit cell volume increases linearly with x, but the Kondo temperature obtained from the specific heat does not change monotonically as expected for the whole series. (C) 2001 Elsevier Science B.V. All rights reserved.