Crystal and magnetic structure of TbNiSnD studied by neutron powder diffraction

The crystal and magnetic structure of TbNiSnD has been studied by neutron powder diffraction. The deuteride crystallizes with the filled TiNiSi type structure (sp. gr. Pnma; a=7.0354(1); b=4.20662(9); c=8.1808(2) A at 293 K; a=7.008(1); b=4.1954(6); c=8.153(1) A at 2 K) and is canted ferromagnetic below 10 K. The deuterium atoms occupy the tetrahedral Tb3Ni sites. The Tb atoms carry a magnetic moment of 6.6(1) μB /Tb. They order antiferromagnetically along the a-axis and ferromagnetically along the c-axis. No significant magnetic moment on the Ni atoms has been observed by neutron diffraction. Insertion of deuterium in TbNiSn induces both a change of the magnetic structure and a reduction of the Tb magnitude of the magnetic moment.