Metallurgical and tow-temperature electronic properties of M1-xUxPd3 (M=Sc, Y, La) alloys

In this paper, we compare the metallurgical and low-temperature electronic properties of the pseudo-binary alloy systems Sc1-xUxPd3 and Y1-xUxPd3 to gain insight into the nature of the non-Fermi-liquid (NFL) behavior observed in these systems at low temperatures. Our results show that both the Sc1-xUxPd3 and Y1-xUxPd3 systems exhibit similar NFL behavior, in spits of significant differences in their metallurgical properties. This comparison provides strong evidence that the NFL behavior is an intrinsic property, and not an extrinsic property driven by metallurgical disorder. Scanning electron microscopy and x-ray-diffraction measurements revealed that the U in the Y1-xUxPd3 system is inhomogeneously distributed on the micron length scale, while the U in the Sc1-xUxPd3 system is nearly homogeneously distributed. However, low-temperature measurements of the electronic specific heat coefficient gamma = C-p/T, magnetic susceptibility chi, and electrical resistivity rho show that the compounds Sc0.7U0.3Pd3 and Y0.8U0.2Pd3 exhibit the following NFL behavior with nearly the same Kondo temperature (PK): C-p/T-proportional to-(1/T-K)In(T/T-K), chi(proportional to)1 - (T/T-K)(1/2), and rho(proportional to)1 - (T/T-K). We also report on the metallurgical properties of the related systems La1-xUxPd3, Y1-xLaxPd3, and La1-xUxPd3.