Magnetic and Magnetocaloric Properties in Sr2RETaO6 (RE = Dy, Ho, and Er) Compounds

Rare earth (RE)-based alloys or compounds with considerable cryogenic magnetocaloric effect (MCE) have been extensively investigated recently due to their potential applications in the field of cryogenic magnetic refrigeration. Herein, three RE-based compounds of Sr2RETaO6 (RE = Dy, Ho, and Er) were fabricated and investigated in detail with regard to their structural, magnetic, and magnetocaloric properties. All the present Sr2RETaO6 compounds crystalize in the double perovskite (DP)-type structure (P21/c space group) with the B site occupied by RE elementals and order magnetically at low temperature. Additionally, considerable cryogenic MCE has been observed in Sr2RETaO6 DP compounds, which were confirmed by a series of MCE merits, including the maximum magnetic entropy change, temperature-averaged entropy change (3 K lift), and relative cooling power. The corresponding values with field change ΔH = 0–70 kOe are found to be 10.55 J·(kgK)−1, 10.18 J·(kgK)−1, 144.67 J·kg−1, to be 7.49 J·(kgK)−1, 7.42 J·(kgK)−1, 198.53 J·kg−1, and to be 8.56 J·(kgK)−1, 8.52 J·(kgK)−1, 142.73 J·kg−1 for Sr2DyTaO6, Sr2HoTaO6 and Sr2ErTaO6 compounds, respectively. These obtained values for the present Sr2RETaO6 compounds are close to most of the recently reported RE-based MCE materials.