Abstrakt
In an antiferromagnetic CePtGe2 (TN = 3.8 K), with two inequivalent Ce sites, the coexistence of a localized f-electron state at the one Ce site and an itinerant heavy-electron state at the other Ce site has been suggested. We have prepared polycrystalline samples of (Ce1-yYy)PtGe2 (y = 0 ~ 1) and have measured the electrical resistivity of y = 0, 0.1, and 0.2.
For y = 0, the resistivity shows the maximum at Tmax ~ 54 K, and below Tmax, it decreases with decreasing temperature. With increasing y, Tmax decreases, and the resistivity for y = 0.2 increases with decreasing temperature down to 4.5 K.
TN evidenced by the downward bend in the resistivity is robust to Y substitution. From these results, a possible shift from the coherent Kondo state to the incoherent Kondo state and the preferential Y substitution to the Ce site with the itinerant heavy-electron state are suggested.