Measurements of the dc susceptibility χ(T), dc magnetization, magnetoresistivity, and magnetostriction are utilized to delineate the magnetic B-T phase diagram of the antiferromagnetically ordered (${\mathit{T}}_{\mathit{N}}$=14 K) heavy-fermion superconductor (${\mathit{T}}_{\mathit{c}}$=2 K) ${\mathrm{UPd}}_2$${\mathrm{Al}}_3$. The single-crystal data reveal three antiferromagnetic phases for B⊥c, but only one for B∥c. The anisotropic χ(T) in the paramagnetic state suggests a tetravalent configuration of uranium.

• Received 14 May 1992

DOI:https://doi.org/10.1103/PhysRevB.46.5818