We studied the properties of the antiferromagnetic (AFM) UNi0.5Sb2 (TN approx 161 K) compound in Sb-flux grown single crystals by means of measurements of neutron diffraction, magnetic susceptibility ({chi}), specific heat (Cp), thermopower (S), thermal conductivity ({kappa}), linear thermal expansion ({Delta}L/L), and electrical resistivity ({rho}) under hydrostatic pressures (P) up to 22 kbar. The neutron diffraction measurements revealed that the compound crystallizes in the tetragonal P42/nmc structure, and the value of the U-moments yielded by the histograms at 25 K is approx 1.85 pm 0.12 {mu}B/U-ion. In addition to the features in the bulk properties observed at TN, two other hysteretic features centered near 40 and 85 K were observed in the measurements of {chi}, S, {rho}, and {Delta}L/L. Hydrostatic pressure was found to raise TN at the rate of approx 0.76 K/kbar, while suppressing the two low temperature features. These features are discussed in the context of Fermi surface and hybridization effects.
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