Magnetism and its connection to non-Fermi-liquid-like behavior

While conducting doping experiments on the recently discovered enhanced effective mass, coexistent antiferromagnetic-superconducting system ${\mathrm{UNi}}_2$ ${\mathrm{Al}}_3$, we have discovered several examples, in samples in which doping has suppressed the magnetic transition at 4.6 K, of unusual temperature dependences of properties consistent with non-Fermi-liquid behavior. Since the other systems discovered to date [${\mathrm{U}}_{0.2}$ ${\mathrm{Y}}_{0.8}$ ${\mathrm{Pd}}_3$, ${\mathrm{UCu}}_{3.5}$ ${\mathrm{Pd}}_{1.5}$, and possibly U(${\mathrm{Pt}}_{0.94}$ ${\mathrm{Pd}}_{0.06}$ ${)}_3$] with similar properties have similar (relatively weak) magnetic behavior, this may be an important clue for understanding, as well as for searching for other systems. Several such systems are discussed, and preliminary results on doped ${\mathrm{UPd}}_2$ ${\mathrm{Al}}_3$ and ${\mathrm{URu}}_2$ ${\mathrm{Si}}_2$ are discussed.