Electrical resistivity of the Kondo systems (Ce1-xLax)TSi3 (T = Rh, Ir)

The electrical resistivities of the pseudo-ternary alloys (Ce1-xLax)TSi3 (T = Rh, Ir; 0 less than or equal to x less than or equal to 1) are reported. The 4f-derived part of their resistivities, rho (4f), is found by subtract ing the temperature-dependent part of the resistivity of LaTSi3. A maximum, characteristic of dense Kondo systems, is obtained in rho (4f) at a temper ature T-max = 105 K for CeRhSi3 and at 130 K for CeIrSi3. T-max decreases f or both compounds with increased La concentration, x. X-ray powder diffract ion was used to measure the increase in tetragonal unit cell volume V for t he (Ce1-xLax)TSi3 alloys with increase in x. The compressible Kondo model i s applied to describe our results of T-max(x) in terms of the on-site Kondo exchange interaction J and the electronic density of states N(E-F) at the Fermi level. The experimental results yield /JN(E-F)/(x=0) = 0.072 +/- 0.01 6 for CeRhSi3 and 0.070 +/- 0.001 for CeIrSi3. (C) 2001 Elsevier Science Lt d. All rights reserved.