Competing effects by Y dilution in CeNiAl4

The occurrence of a maximum at a temperature T max in the resistivity of the dense Kondo compound CeNiAl4 and in (Ce1−xY x)NiAl4 alloys is investigated. T max ( ∝ T K , the Kondo temperature) first increases, goes through a maximum value and decreases with increase in x . This behaviour is qualitatively explained by considering the competing influence of volume changes and dilution (the Kondo-hole effect) on the Kondo system. Complementary magnetic susceptibility measurements corroborate these results.