Electronic properties of single crystalline UNi0.39Rh0.61Al

U(Ni,Rh)Al alloys crystallize in the hexagonal ZrNiAl structure. Here, we report on measurements on a single crystalline member of this series, namely, UNi0.39Rh0.61Al. Similar to other members of this series, this compound exhibits highly anisotropic properties with the easy-magnetization direction along the c-axis. We report in the results of electrical resistance, magnetoresistance, and thermal expansion as a function of temperature (2-300 K) and applied magnetic field (0-18 T). The results provide strong evidence for antiferromagnetic ordering at T-N <= 15 K followed by a ferromagneticlike (ferro-or ferrimagnetic) transition around 7 K (we use the term "ferromagneticlike" because, based on our bulk data, we cannot exclude canted moments with antiferromagnetic components or ferromagnetic order of two different moments). A magnetic B-T phase diagram for UNi0.39Rh0.61Al is proposed. (c) 2008 American Institute of Physics.