Amplitude-modulated spin structure in Er5Sn3 above 10 K

Neutron diffraction has been performed on the intermetallic Er5Sn3 crystall izing in the Mn5Si3-type structure with space group P6(3)/mcm. The unit cel l constants are a = 8.733 Angstrom and c = 6.369 Angstrom. Er5Sn3 orders an tiferromagnetically below 32 K with an incommensurate sine wave-modulated m agnetic structure. The magnetic propagation vector and the spin orientation s are along the c-axis. The magnitude of the Er-moments are 9.44 and 4.33 m u(B) for the 4d and 6g sites, respectively, at 14 K. New magnetic reflectio ns appear below 8 K giving rise to an unknown magnetic structure. (C) 2000 Elsevier Science S.A. All rights reserved.