A Dense Metal–Organic Framework for Enhanced Magnetic Refrigeration

Enhanced Magnetocaloric Effect from Cr Substitution in Ising Lanthanide Gallium Garnets Ln3CrGa4O12 (Ln = Tb, Dy, Ho)

“…) to be extracted in high magnetic fields makes it an ideal MCM for T < 20 K. [14][15][16] In recent years, a number of Gd containing MCMs with better performance at 2 K have been reported [17][18][19][20] but GGG continues to be used and serves as the benchmark for MCMs in this temperature regime. However, for all the Gd-based magnetocalorics, the change in magnetic entropy is maximized in fields of 5 T or higher.…”

“…[13] Of these, gadolinium gallium garnet (GGG), which shows no long-range ordering down to 25 mK, has been established as a MCM for magnetic refrigeration in the liquid helium temperature regime. The absence of long-range ordering, high density of magnetic ions, chemical stability, and lack of single ion anisotropy (L = 0 for Gd 3+ ) allowing for the full magnetic entropy (Rln[2J + 1] = 17.29 J K −1 mol Gd −1 ) to be extracted in high magnetic fields makes it an ideal MCM for T < 20 K. [14][15][16] In recent years, a number of Gd containing MCMs with better performance at 2 K have been reported [17][18][19][20] but GGG continues to be used and serves as the benchmark for MCMs in this temperature regime. However, for all the Gd-based magnetocalorics, the change in magnetic entropy is maximized in fields of 5 T or higher.…”

Magnetocaloric effect in gadolinium-oxalate framework Gd2(C2O4)3(H2O)6⋅(0⋅6H2O)

“…antiferromagnetic interactions, such as the compact metal-organic framework (MOF) Gd(HCOO) 3 which takes advantage of formate, the lightest carboxylate. 18 Finally, we notice the advantages of certain magnetocaloric MOF materials in terms of robustness, which can be considered as an advantage in practical applications as we emphasized in the past with the study of Gd(HCOO)(C 8 H 4 O 4 ). 19 Following the above-described tendency in the research field of molecular magnetic coolers, we thought that gadolinium oxalate could be an interesting candidate.…”

Cs2NaAl1−xCrxF6: A family of compounds presenting magnetocaloric effect

“…Common materials that display large MCEs below 80 K are intermetallic systems such as ErAl 2 and DyNi 2 , which show temperature changes of T ad ≈ 10 K (at T = 13 K) and T ad ≈ 14 K (at T = 21 K), under H = 50 kOe, [17] Gd(HCOO) 3 30 ∼50 ∼20 (at 1 K) [12] ErAl 2 50 37 10 (at 13 K) [46] DyNi 2 50 21 8 (at 21 K) [46] respectively [46]. Turning to the analysis of T ad results in Fig.…”

“…Although some of these compounds have S T values comparable to the Gd-standard material, of about 3.4 J/kg K for a field variation of H = 10 kOe close to room temperature [10], there are other systems that have a much larger entropy change, S T ≈ 30 J/kg K under H = 50 kOe, at 5 K, such as Gd 3 Ga 5−x Fe x O 12 [6]. Other successful examples consist of perovskite-type oxides [11], metal-organic frameworks containing gadolinium [12], and molecular nanomagnets, such as Mn 32 [13] and Fe 14 [14]. However, very few studies have so far reported on caloric effects in fluoride systems [15][16][17], which is the aim of this paper.…”