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High pressure investigation of the heavy-fermion antiferromagnet U_3Ni_5Al_19

E. D. Bauer·V. A. Sidorov·S. Bobev·D. J. Mixson·J. D. Thompson·J. L. Sarrao·M. F. Hundley
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Abstract

Measurements of magnetic susceptibility, specific heat, and electrical resistivity at applied pressures up to 55 kbar have been carried out on single crystals of the heavy-fermion antiferromagnet U_3Ni_5Al_19, which crystallizes in the Gd_3Ni_5Al_19 orthorhombic structure with two inequivalent U sites. At ambient pressure, a logarithmic T-dependence of the specific heat and T-linear electrical resistivity below 5 K indicates non-Fermi liquid (NFL) behavior in the presence of bulk antiferromagnetic order at T_N=23 K. Electrical resistivity measurements reveal a crossover from non-Fermi liquid to Fermi liquid behavior at intermediate pressures between 46 kbar and 51 kbar, followed by a return to NFL T^{3/2} behavior at higher pressures. These results provide evidence for an ambient pressure quantum critical point and an additional antiferromagnetic instability at P_c=60 kbar.

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E. D. Bauer, V. A. Sidorov, S. Bobev, D. J. Mixson, J. D. Thompson, J. L. Sarrao, M. F. Hundley. 2004-09-08. High pressure investigation of the heavy-fermion antiferromagnet U_3Ni_5Al_19. https://doi.org/10.1103/physrevb.71.014419

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