Effects of Ge substitution for Sn on the crystal structure, magnetization, and the magnetocaloric effect of Mn3SnC

The effects of a Ge substitution for 50% Sn on the crystal structure, magnetization and the magnetocaloric effect of Mn3SnC were investigated using high-resolution X-ray diffraction, magnetic and calorimetric measurements. Results show that the Ge substitution enlarges the magnetovolume effect, though it reduces the lattice parameter. On the other hand, the Ge substitution increases high field magnetization and reduces the Curie temperature. The Ge substitution also reduces latent heat during the ferrimagnetic transition and the magnetocaloric effect at the magnetic field change 0–5 T. It is suggested that the Ge substitution perhaps reduces the electronic entropy change via a change of the electronic structure and its stability against an external magnetic field. This effect is dominant over an increase of the magnetic entropy change leading to the reduction of the magnetocaloric effect.