Magnetic Properties of the ErFe Ga Si Compounds

The ErFe Ga Si compounds with the ThMn -type structure were synthesized for , 0.5, 1.0, 1.5 and 2.0. With increasing Ga content, the lattice constant c and the unit-cell volume V increase monotonically. The lattice constant, a, and the Curie temperature increase first, go through a maximum and then decrease with increasing . Spin re-orientation from the easy-cone to the uniaxial type is detected for all the compounds as the temperature increases from 5 K to 300 K. A tentative spin phase diagram is constructed for ErFe Ga Si . The saturation magnetization decreases monotonically which can be understood in terms of a simple dilution model.