Neutron diffraction at the magnetic structure of Mn0.88Fe0.12WO4

Neutron diffraction of a single crystal and of powder samples of compositio n Mn0.88Fe0.12WO4 were performed to study the magnetic structure. A commens urate antiferromagnetic (AF) structure with the wavevector k = (0.25 0.5 0. 5) between 1.5 and 13.5 K and an incommensurate AF structure with k = (0.23 0.5 0.508) mere determined. A magnetic phase similar to that of FeWO4 is o bserved between 19 and 13.3 K. Below 13.3 K magnetic diffraction intensitie s indexed to the magnetic unit. cell of FeWO4 are still present, however, c annot be related to the FeWO4-type structure alone. (C) 2000 Elsevier Scien ce B.V. All rights reserved.