The Magnetic Structure of NpPd2Al3 : Relevance to the Co-Existence of Superconductivity and Magnetism in UPd2Al3

We report neutron diffraction experiments to determine the low-temperature magnetic structure of NpPd2Al3, the isostructural Np analog of the heavy-fermion superconductor UPd2Al3. The system orders initially at about 40K with an incommensurate magnetic propagation vector q = (1/3, 1/3, 0.36). Below 25K the intensity of this phase is reduced and a new commensurate magnetic phase with q = (1/3, 1/3, 1/2) is observed as the dominant phase. the fact that we observe two magnetic phases in this system may have relevance to understanding the ground state in UPd2Al3.

HIESS Arno;  BOURDAROT F.;  BURLET P.;  RESSOUCHE E.;  SANCHEZ J.P.;  WASTIN Franck Henri;  REBIZANT Jean;  SUARD E.;  LANDER Gerard Heath; 

1996-11-05

JRC13685