Magnetic properties of Mn-rich Rh2Mn1+xSn1−x Heusler alloys

X-ray powder diffraction and magnetization measurements have been carried out on Rh2Mn1+xSn1−x (0≤x≤0.3) alloys. The alloys, which crystallize in the L21 structure, were found to exhibit ferromagnetic behavior. The lattice constant a at room temperature decreases with increasing x, whereas the Curie temperature TC decreases linearly. At 5 K the magnetic moment per formula unit first increases with increasing x and then saturates for x≥0.2. The experimental results are discussed in terms of the influence of the Mn–Mn exchange interactions between the Mn atoms on the Sn and Mn sites.