Exploring the Electronic Structure and Magnetic Properties of Sm2MgMnO6 Double Perovskite.

In this article, we have investigated the electronic structure and magnetic properties of Sm₂MgMnO₆ prepared through auto-combustion method. The first principles of the density-functional theory have been applied to study of the electronic structure. The oxidation states of Mn and Mg are Mn³⁺/Mn⁴⁺ and Mg²⁺, respectively. The existence of Mn³⁺ is higher than Mn⁴⁺. The magnetic study reveals the sample shows ferromagnetic to paramagnetic transition at around 13.5 K which is followed by an antiferromagnetic ordering at 8.3 K. Antiferromagnetic and ferromagnetic ordering have been identified at 8.3 K and higher temperature, respectively. Sm₂MgMnO₆ shows a maximum magnetic entropy change of 1.25 J kg^-1K^-1 and relative cooling power of 86.9 J/kg for a field variation of 70 kOe near 25 K. The values are comparable to many double perovskites reported previously. This study highlights that Sm₂MgMnO₆ is a potential material for magnetocaloric refrigerant at low temperature. [ABSTRACT FROM AUTHOR]