UC Irvine

We present the results of electronic transport, magnetic susceptibility, and thermodynamic measurements on single crystals of the cubic compound Ce3Bi4Pt3. The susceptibility displays a broak peak centered at Tmax = 80K, which in Ce compounds is usually indicative of mixed valence and moderately heavy-electron behavior. Both the electronic transport properties and the low-temperature specific heat indicate that Ce3Bi4Pt4 is nonmetallic with a transport energy gap of roughly 35 K. We argue that this temperature is close to that scale over which coherence should develop in a periodic metallic system with Tmax = 80K. Resistivities typical of a Kondo-impurity system are realized when the compound is alloyed with moderate amounts of lanthanum. Further, lanthanum substitution increases the low-temperature specific heat to a value consistent with the single-ion energy scale determined from the magnetic susceptibility. © 1991.