The Tb-Fe-Ga system at 870 ​K as a representative of rare-earth iron gallides: Crystal structure and magnetic properties

The Tb-Fe-Ga system has been investigated at 870 ​K by X-ray powder, microprobe elemental analyses and magnetic measurements. The existence of the known compounds TbFe6.2-5.5Ga5.8-6.5 (ScFe6Ga6-type), TbFe5.5-4.9Ga6.5-7.1 (ThMn12-type), TbFe2.4-2.2Ga0.6-0.8 (CeNi3-type), Tb4FeGa12 (Y4PdGa12-type) and quasibinary solid solutions Th2Zn17-type Tb2Fe17-10.6Ga0-6.4, PuNi3-type TbFe3-2.73Ga0-0.23 and MgCu2-type TbFe2-1.57Ga0-0.43 has been confirmed, meanwhile new Th2Ni17-type Tb1.85Fe15.2Ga1.8 and AlB2-type TbFe0-0.3Ga2-1.7 were detected at 870 ​K. The appreciable solubility was no observed at the other binary compounds in the Tb-Fe-Ga system. Tb4FeGa12 is pure antiferromagnetic and TbFe0.3Ga1.7 shows mixed field-sensitive ferro-antiferromagnetic ordering. TbFe6.2Ga5.8, TbFe5.5Ga6.5, TbFe2.4Ga0.6, and TbFe1.42Ga0.58 exhibit ferrimagnetic ordering of Tb- and Fe-sublattices, which are soft ferromagnets at room temperature and hard magnets at low temperatures.