Pressure-induced non-Fermi-liquid behavior in a heavy-fermion compoundCe7Ni3

Under increasing pressure, the N{acute e}el temperature of the heavy-fermion compound Ce{sub 7}Ni{sub 3} (T{sub N}=1.9 K for {ital P}=0) decreases and vanishes near P{sub c}{approx}0.33 GPa. Non-Fermi-liquid behavior appears at 0.4 GPa in both the specific heat and ac magnetic susceptibilitiy, C{sub m}/T{approximately}{minus}lnT and {chi}{sub ac}{proportional_to}(1{minus}{alpha}T{sup 1/2}). Above 0.62 GPa, the normal Fermi-liquid state recovers, as indicated by the {ital T} independence of C{sub m}T and the T{sup 2} dependence of the magnetic resistivity. The observed crossover with pressure is described by self-consistent renormalization theory of spin fluctuations (SF) in terms of the characteristic SF temperature T{sub 0} which increases by a factor of 20 for 0.33{le}{ital P}{le}0.75 GPa. {copyright} {ital 1997} {ital The American Physical Society}