Thermoelectric power and resistivity studies in the Kondo-lattice system CeGa₂ with Sn or Al substitutions and RGa₂ (R identical to Ho,Dy,Tb) alloys

Resistivity rho and thermopower S studies between 1.7 and 300 K have been carried out to examine Kondo and magnetic ordering effects in Ce(Ga_1-xSn_x)₂, Ce(Ga_0.9Al_0.1)₂ and RGa₂ (R identical to Ho,Dy,Tb) alloys. Evidence for the presence of the Kondo effect in CeGa₂ was deduced from the high-temperature logarithmic variation observed in the rho data, supporting the conclusions of the earlier neutron studies. In the Sn-doped alloys (x>0.1), the Kondo effect is also found to be present as observed through the evolution of rho _min. Such a rho _min behaviour is not seen in the case of pure CeGa₂ alloy. Further, for the Sn-doped alloys, the magnetic ordering temperature is depressed compared with the pure CeGa₂ alloy. The development of the low-temperature magnetic order was found in RGa₂ as well as in the Al-doped alloy, whereas both Kondo and magnetic ordering effects were observed in the Sn-doped samples.