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Excellent magnetocaloric properties in RE 2 Cu 2 Cd ( RE   =   Dy and Tm) compounds and its composite materials

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ABSTRACT

The magnetic properties and magnetocaloric effect (MCE) of ternary intermetallic RE2Cu2Cd (RE = Dy and Tm) compounds and its composite materials have been investigated in detail. Both compounds undergo a paramagnetic to ferromagnetic transition at its own Curie temperatures of TC ~ 48.5 and 15 K for Dy2Cu2Cd and Tm2Cu2Cd, respectively, giving rise to the large reversible MCE. An additionally magnetic transition can be observed around 16 K for Dy2Cu2Cd compound. The maximum values of magnetic entropy change (−ΔSMmax) are estimated to be 17.0 and 20.8 J/kg K for Dy2Cu2Cd and Tm2Cu2Cd, for a magnetic field change of 0–70 kOe, respectively. A table-like MCE in a wide temperature range of 10–70 K and enhanced refrigerant capacity (RC) are achieved in the Dy2Cu2Cd - Tm2Cu2Cd composite materials. For a magnetic field change of 0–50 kOe, the maximum improvements of RC reach 32% and 153%, in comparison with that of individual compound Dy2Cu2Cd and Tm2Cu2Cd. The excellent MCE properties suggest the RE2Cu2Cd (RE = Dy and Tm) and its composite materials could be expected to have effective applications for low temperature magnetic refrigeration.

No MeSH data available.


The magnetic entropy change −ΔSM as a function of temperature for various magnetic field changes ΔH up to 0–70 kOe for Dy2Cu2Cd (a) and Tm2Cu2Cd (b) compounds, respectively. Insets of (a,b) show the maximum values of magnetic entropy change (−ΔSMmax) as a function of the magnetic field changes for Dy2Cu2Cd and Tm2Cu2Cd compounds, respectively.
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f5: The magnetic entropy change −ΔSM as a function of temperature for various magnetic field changes ΔH up to 0–70 kOe for Dy2Cu2Cd (a) and Tm2Cu2Cd (b) compounds, respectively. Insets of (a,b) show the maximum values of magnetic entropy change (−ΔSMmax) as a function of the magnetic field changes for Dy2Cu2Cd and Tm2Cu2Cd compounds, respectively.

Mentions: Figure 5(a,b) show the temperature dependence of magnetic entropy change −ΔSM for Dy2Cu2Cd and Tm2Cu2Cd compounds which is derived from the temperature and field dependence of the magnetization M (H, T) by using the Maxwell’s thermodynamic relation27, , respectively. It can be found that the maximum value of −ΔSM increases monotonically with increasing magnetic field change for both compounds [see insets of Fig. 5(a,b)]. Two successive −ΔSM peaks (one at around TC, another at around TS) can be clearly seen even the low magnetic field change for Dy2Cu2Cd compound, thus obviously enlarging the temperature range of MCE. Only a pronounced peak in the −ΔSM(T) curves is observed around TC for Tm2Cu2Cd compound. For the magnetic field changes of 0–20, 0–50, and 0–70 kOe, the maximum values of the magnetic entropy change (−ΔSMmax) are evaluated to be 7.2, 13.8, and 17.0 J/kg K around TC, and 3.3, 6.6, and 8.3 J/kg K around TS for Dy2Cu2Cd compound; and to be 9.2, 17.3 and 20.8 J/kg K for Tm2Cu2Cd compound, respectively.


Excellent magnetocaloric properties in RE 2 Cu 2 Cd ( RE   =   Dy and Tm) compounds and its composite materials
The magnetic entropy change −ΔSM as a function of temperature for various magnetic field changes ΔH up to 0–70 kOe for Dy2Cu2Cd (a) and Tm2Cu2Cd (b) compounds, respectively. Insets of (a,b) show the maximum values of magnetic entropy change (−ΔSMmax) as a function of the magnetic field changes for Dy2Cu2Cd and Tm2Cu2Cd compounds, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5035927&req=5

f5: The magnetic entropy change −ΔSM as a function of temperature for various magnetic field changes ΔH up to 0–70 kOe for Dy2Cu2Cd (a) and Tm2Cu2Cd (b) compounds, respectively. Insets of (a,b) show the maximum values of magnetic entropy change (−ΔSMmax) as a function of the magnetic field changes for Dy2Cu2Cd and Tm2Cu2Cd compounds, respectively.
Mentions: Figure 5(a,b) show the temperature dependence of magnetic entropy change −ΔSM for Dy2Cu2Cd and Tm2Cu2Cd compounds which is derived from the temperature and field dependence of the magnetization M (H, T) by using the Maxwell’s thermodynamic relation27, , respectively. It can be found that the maximum value of −ΔSM increases monotonically with increasing magnetic field change for both compounds [see insets of Fig. 5(a,b)]. Two successive −ΔSM peaks (one at around TC, another at around TS) can be clearly seen even the low magnetic field change for Dy2Cu2Cd compound, thus obviously enlarging the temperature range of MCE. Only a pronounced peak in the −ΔSM(T) curves is observed around TC for Tm2Cu2Cd compound. For the magnetic field changes of 0–20, 0–50, and 0–70 kOe, the maximum values of the magnetic entropy change (−ΔSMmax) are evaluated to be 7.2, 13.8, and 17.0 J/kg K around TC, and 3.3, 6.6, and 8.3 J/kg K around TS for Dy2Cu2Cd compound; and to be 9.2, 17.3 and 20.8 J/kg K for Tm2Cu2Cd compound, respectively.

View Article: PubMed Central - PubMed

ABSTRACT

The magnetic properties and magnetocaloric effect (MCE) of ternary intermetallic RE2Cu2Cd (RE = Dy and Tm) compounds and its composite materials have been investigated in detail. Both compounds undergo a paramagnetic to ferromagnetic transition at its own Curie temperatures of TC ~ 48.5 and 15 K for Dy2Cu2Cd and Tm2Cu2Cd, respectively, giving rise to the large reversible MCE. An additionally magnetic transition can be observed around 16 K for Dy2Cu2Cd compound. The maximum values of magnetic entropy change (−ΔSMmax) are estimated to be 17.0 and 20.8 J/kg K for Dy2Cu2Cd and Tm2Cu2Cd, for a magnetic field change of 0–70 kOe, respectively. A table-like MCE in a wide temperature range of 10–70 K and enhanced refrigerant capacity (RC) are achieved in the Dy2Cu2Cd - Tm2Cu2Cd composite materials. For a magnetic field change of 0–50 kOe, the maximum improvements of RC reach 32% and 153%, in comparison with that of individual compound Dy2Cu2Cd and Tm2Cu2Cd. The excellent MCE properties suggest the RE2Cu2Cd (RE = Dy and Tm) and its composite materials could be expected to have effective applications for low temperature magnetic refrigeration.

No MeSH data available.