Neutron powder diffraction determination of the magnetic structure of Gd_3Ag_4Sn_4

摘要

Natural gadolinium is the strongest neutron-absorbing element and neutron diffraction studies of Gd-containing materials rely on the use of either enriched Gd isotopes or short neutron wavelengths where the absorption is weaker but, unfortunately, the neutron flux is also weak. We have employed a new sample-mounting technique to obtain neutron powder diffraction patterns from the intermetallic compound Gd3Ag4Sn4 containing natural Gd, at a neutron wavelength of— 2.37 A where there is much greater flux. Here, we report the magnetic structure of Gd_3Ag_4Sn_4. The magnetic ordering temperature is 28.8(2) K. At 2.8 K the Gd(4e) sublattice is antiferromagnetically ordered along the crystal c-axis, commensurate with the crystal lattice. The Gd(2d) sublattice is also ordered along the c-axis but its magnetic structure is incommensurate with the crystal lattice.