Neutron diffraction study of HfFe6Ge6-type TmMn6Sn6−xInx compounds (0.4≤x≤1.0)

Abstract The HfFe6Ge6-type structure TmMn6Sn6, TmMn6Sn5.9Ga0.1, TmMn6Sn5.8Ga0.2, TmMn6Sn5.5Ga0.5, TmMn6Sn4Ga2 and TmMn6Sn3.5Ga2.5 compounds have been studied by powder neutron diffraction. TmMn6Sn6 orders antiferromagnetically below TN=347 K and displays a colinear antiferromagnetic structure above 330 K while a triple spiral structure with wave vector (0, 0, qz) occurs in the 2–330 K range. TmMn6Sn5.9Ga0.1 (TN=343 K) displays a triple spiral structure above 40 K and a cone structure below 40 K. TmMn6Sn5.8Ga0.2 orders ferrimagnetically (Tc=353 K) and exhibits a reentrant ferrimagnetic behaviour in the 106–329 K range where it displays a triple spiral structure. Below 106 K, a ferrimagnetic structure with moment directions close to the (001) plane is observed. TmMn6Sn5.5Ga0.5 behaves ferrimagnetically in its whole ordered range (Tc=366 K) and is characterized by an easy plane magnetization. TmMn6Sn4Ga2 and TmMn6Sn3.5Ga2.5 display ferrimagnetic ordering (Tc=254 and 204 K) and are characterized by easy axis magnetization. In their paramagnetic state, the neutron diffraction study indicates that the Ga atoms occupy the (2c) position and are close to the Tm atoms.