Giant reversible magnetocaloric effect in antiferromagnetic GdCo2B2 compound

Abstract

The magnetocaloric effect of GdCo2B2 was studied by magnetization and heat capacity measurements. A giant reversible magnetocaloric effect has been observed which is related to a field-induced first order metamagnetic transition from antiferromagnetic to ferromagnetic state. The values of maximum magnetic entropy change (−ΔSMmax) reach 9.3 and 21.5 J kg−1 K−1 for the field change of 2 and 7 T with no obvious hysteresis loss around 25 K, respectively. The corresponding maximum adiabatic temperature changes (ΔTadmax) are evaluated to be 6.7 and 18.9 K. These values are even larger than some of potential magnetic refrigerant materials reported in the same temperature range and also comparable to the room temperature giant magnetocaloric materials. These results indicated that GdCo2B2 could be a promising candidate for magnetic refrigeration at low temperatures.

Study of the magnetic properties and magnetocaloric effect in RCo2B2 (R = Tb, Dy and Ho) compounds

“…4. A clear negative slope at low temperature and low magnetic field region for TbCo 2 B 2 indicate the first order magnetic phase transition which is similar to that of ErRu 2 Si 2 [31] and GdCo 2 B 2 [32] compounds. In contrast, neither the inflection point nor negative slopes can be observed for DyCo 2 B 2 and HoCo 2 B 2 , providing the occurrence of a second order magnetic transition which is similar to that of PrCo 2 B 2 [33] and NdCo 2 B 2 [34] compounds.…”

“…Very recently, Samanta et al and Li et al systematically studied the magnetic properties and MCE in RRu 2 Si 2 (R ¼ Gd and Er) [30,31] and RCo 2 B 2 (R ¼ Gd, Pr and Nd) [32e34] compounds (belong to RT 2 X 2 series compounds), respectively. A giant MCE in antiferromagnetic ErRu 2 Si 2 [31] and GdCo 2 B 2 [32] compounds around its ordering temperature was observed, which was associated with a fieldinduced first order magnetic transition from antiferromagnetic (AFM) to ferromagnetic (FM) state below the (zero field) AFM transition temperature. To further understand the physical properties of RCo 2 B 2 system and searching new materials displaying large MCE, the present work extended the study of magnetism and MCE of RCo 2 B 2 system to R ¼ Tb, Dy and Ho.…”

Large magnetocaloric effect in TbCo3B2 compound

“…The RCo 3 B 2 compounds are paramagnetic at room temperature and undergo a Co-Co sublattice magnetic order transition at ∼160 (20) K. In addition, a second R-R sublattice magnetic order transition was also observed at 54, 47, 28 and 22 K for R = Gd, Sm, Tb and Dy, respectively [12][13][14][15]. Very recently, a giant/large reversible MCE in ternary R-Co-B intermetallic compounds RCo 2 B 2 (R = Gd, Pr and Nd) [16][17][18] was reported, respectively. To search new material displaying large MCE and further understand the physical properties of RCo 3 B 2 system, in this paper, the magnetic properties and MCE in TbCo 3 B 2 were systematically studied.…”

Magnetic properties and magnetocaloric effect in GdCo3B2 compound

“…The RCo 3 B 2 compounds are paramagnetic at room temperature and undergo a Co-Co sublattice magnetic order transition at ∼160 (20) K. In addition, a second R-R sublattice magnetic order transition was also observed at 54, 47, 28 and 22 K for R = Gd, Sm, Tb and Dy, respectively [12][13][14][15][16][17][18][19]. Among all the rare-earth transition metal compounds, Gd-based systems [20][21][22] have been extensively investigated owning to that Gd ion has the largest spinorial moment and has the highest effective exchange coupling around room temperature. In addition, Gd ion has no orbital moment in its ground state, which makes it simple for understanding the magneto-thermal behaviour occurring in various compounds containing Gd.…”