MAGNETIC-ORDERING AND SUPERCONDUCTING PROPERTIES OF HO-X(LU DY)(1-X)NI-2 (B2C)-B-11/

We investigated the magnetic structure of HoxLu1-xNi2 (B2C)-B-11 for x = 1, 0.95, 0.85 and 0.75 and HoxDy1-xNi2 (B2C)-B-11 for x = 0.85, 0.7 0, 0.40 and 0 by means of neutron diffraction as a function of tempera ture between 2 and 15 K in zero external field. We observed several ma gnetic phases, one with commensurate (0 0 I)and two with incommensurat e wave vectors, (0 0 0.915) and (0.585 0 0). Only the temperature: dep endence of the a-axis modulation coincides with the reentrant behavior found for all investigated HoxLu1-xNi2 (B2C)-B-11 samples by resistan ce measurements. For HoxDy1-xNi2 (B2C)-B-11 we found only c-axis modul ated structures : the commensurate for all samples and the incommensur ate for x greater than or equal to 0.7. (C) 1998 Published by Elsevier Science B.V. All rights reserved.