Recent studies of pseudoquaternary, doped systems or solid solutions o
f heavy fermion and superconducting materials have been started in an
attempt to understand their unusual behavior. To resolve the physics,
the characterization of the studied samples, and particularly their ho
mogeneity, is of crucial importance. We present here a detailed charac
terization of (U1-xNpx)Ru2Si2 and (U1-xNpx)Pd2Al3 alloys by X-ray diff
raction, metallography and microprobe analysis. The U and Np atoms wer
e shown to be homogeneously distributed and the samples were found to
be single phase of uniform composition. (C) 1998 Elsevier Science S.A.