Crystal structure and magnetic properties of the new ternary actinide compounds AnPd5Al2 (An = U, Np)

We report the crystal structure and magnetic properties of new ternary actinide compounds UPd5Al2 and NpPd5Al2. Both compounds crystallize in the body-centered tetragonal ZrNi2Al5-type tetragonal structure (I 4/mmm). Although the magnetic susceptibility of both compounds follows the Curie–Weiss behavior at high temperature, no magnetic phase transition was observed. UPd5Al2 has a nonmagnetic ground state where the magnetic susceptibility saturates at low temperature, while NpPd5Al2 superconducts below 4.9 K as reported recently.