Magnetocaloric properties of Gd2MoO6 prepared by a simple and fast method

Gd3TeBO9: A Rare‐Earth Borate with Significant Magnetocaloric Effect

“…Just like Gd 2 MoO 6 and Gd 2 Ti 2 O 7 , the high Gd concentration does not bring them a large magnetic entropy change (Figure 8), and the more negative Curie-Weiss temperature seems to indicate the existence of strong antiferromagnetic interaction inside them (Gd 2 MoO 6 @θ = À 6.41 K, Gd 2 Ti 2 O 7 @θ = À 9.6 K). [14,15,35] Possible solutions include the precise design and optimization of the crystal structure, for example, the magnetically frustrated structure is considered to possibly increase the peak of magnetic entropy change and lower the temperature at the peak. [27,28,36] The measurements of heat capacity can further characterize the cooling power of the sample.…”

“…Figure 8 shows many Gd-based compounds with excellent magnetocaloric properties. [4][5][6][7][8][9][10][11][12][13][14][15][16][17]21] Obviously, the magnetic entropy change of Gd 3 TeBO 9 is better than most Gd-based compounds. Especially in the comparison of magnetic entropy change per unit volume [Figure 8(b)], Gd 3 TeBO 9 's ranking improved from fourth to second, with an equivalent magnetic entropy change per unit volume to that of Gd 3 WBO 9 [408 mJ/ (cm 3 K)], [17] and higher than compounds with a larger magnetic entropy change per unit mass [GdPO 4 and LiCaGd 5 (BO 3 ) 6 ].…”

“…Usually, it is difficult to satisfy the two at the same time, because higher Gd 3+ concentration generally leads to shorter Gd−Gd distance, resulting in a stronger antiferromagnetic exchange effect. Just like Gd 2 MoO 6 and Gd 2 Ti 2 O 7 , the high Gd concentration does not bring them a large magnetic entropy change (Figure 8), and the more negative Curie‐Weiss temperature seems to indicate the existence of strong antiferromagnetic interaction inside them (Gd 2 MoO 6 @ θ =−6.41 K, Gd 2 Ti 2 O 7 @ θ =−9.6 K) [14,15,35] . Possible solutions include the precise design and optimization of the crystal structure, for example, the magnetically frustrated structure is considered to possibly increase the peak of magnetic entropy change and lower the temperature at the peak [27,28,36] …”

“…Figure 8 shows many Gd‐based compounds with excellent magnetocaloric properties [4–17,21] . Obviously, the magnetic entropy change of Gd 3 TeBO 9 is better than most Gd‐based compounds.…”

“…Furthermore, the maximum magnetic entropy changes of Gd-based compounds reported in a large number of literatures appear in the liquid helium temperature region (even lower), [3] which is beneficial to reduce the consumption of liquid helium, a severely scarce resource. At present, the magnetocaloric effect of various types of Gd-based compounds has been reported, including Gd-based oxides, [4][5][6][7][8][9][10][11][12][13][14][15][16][17] Gd-based molecular clusters, [18][19][20][21] Gd-based halides, [22] etc. Among them, Gdbased oxides, such as Gd 3 Ga 5 O 12 (GGG), have the advantages of fast magnetization/demagnetization speed, high environmental stability, high corrosion resistance, and simple preparation process, [23,24] were put into practical use.…”