  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.
