Large magnetocaloric effect in the EuSe1− x S x magnetic semiconductors with coexistence of the magnetic phases

We present the experimental results of the magnetic and calorimetric properties as well as the magnetocaloric effect of the EuSe1−xSx compounds with x = 0, 0.10, 0.16, 0.18, and 1. Magnetic and calorimetric results reveal complex low-temperature magnetic behavior arising from competing exchange interactions, leading to the coexistence of antiferromagnetic, ferrimagnetic, and ferromagnetic phases. Both first-order and second-order magnetic phase transitions are observed. With increasing sulfur concentration, the Curie temperature (TC) systematically increases, whereas the Néel temperature (TN) decreases. Structural analysis shows a linear reduction of the lattice parameter from 6.195 to 5.975 Åwith sulfur substitution, which is associated with the observed metamagnetic behavior. A large magnetocaloric effect is obtained, with a maximum magnetic entropy change of −ΔSm value of 34.2 J kg−1 K−1 at 5 T for EuSe0.84S0.16. These results demonstrate that EuSe1−xSx compounds are attractive candidates for low-temperature magnetic refrigeration applications.