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Magnetic entropy change and magnetocaloric effect of DyNiSi <inf>3</inf> , Dy <inf>2</inf> Ni <inf>3</inf> Si <inf>5</inf> , DyNiSi <inf>2</inf> and HoNiSi <inf>0.33</inf> Ga <inf>67</inf> antiferromagnets
Date Issued
01-04-2019
Author(s)
Morozkin, A. V.
Yapaskurt, V. O.
Yao, Jinlei
Indian Institute of Technology, Madras
Quezado, S.
Malik, S. K.
Abstract
Magnetic properties, magnetic entropy change and magnetocaloric effect of the polycrystalline SmNiGe 3 -type DyNiSi 3 , U 2 Co 3 Si 5 -type Dy 2 Ni 3 Si 5 , CeNiSi 2 -type DyNiSi 2 and CeCu 2 -type HoNiSi 0.33 Ga 0.67 antiferromagnets have been studied by bulk magnetization measurements. In field of 100 Oe DyNiSi 3 , Dy 2 Ni 3 Si 5 , DyNiSi 2 and HoNiSi 0.33 Ga 0.67 show Néel temperature (T N ) of 21 K, 19 K, 9 K and 4 K, respectively. At 2 K, above critical field (H crit ) of 28 kOe for DyNiSi 3 , 10 kOe for Dy 2 Ni 3 Si 5 , 25 kOe for DyNiSi 2 and ∼1 kOe for HoNiSi 0.33 Ga 0.67 they are soft ferromagnets and HoNiSi 0.33 Ga 0.67 shows ferromagnetic ordering below T C = 5 K in a field of 5 kOe. Magnetic entropy changes (ΔS m ) of DyNiSi 3 , Dy 2 Ni 3 Si 5 , DyNiSi 2 and HoNiSi 0.33 Ga 0.67 exhibit high-temperature negative and low temperature positive components around Néel temperature up to critical field with decreasing and disappearance of positive component of ΔS m above critical field, which indicates the transformation from antiferromagnetic to ferromagnetic states. From these compounds, HoNiSi 0.33 Ga 0.67 shows largest magnetic entropy change of −15.4 J/kg⋅K at 8 K for a field change of 0–50 kOe.
Volume
107