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

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.


Related in: MedlinePlus

(a) Magnetic field dependence of the magnetization (increasing field only) for Tm2Cu2Cd at some selected temperatures. (b) The plots of H/M versus M2 for Tm2Cu2Cd at some selected temperatures.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5035927&req=5

f4: (a) Magnetic field dependence of the magnetization (increasing field only) for Tm2Cu2Cd at some selected temperatures. (b) The plots of H/M versus M2 for Tm2Cu2Cd at some selected temperatures.

Mentions: The magnetic isothermal M(H) curves of Dy2Cu2Cd and Tm2Cu2Cd compounds with increasing field around their transition temperatures with increasing magnetic field up to 70 kOe have been measured and some of them are shown in Figs 3(a) and 4(a), respectively. The magnetization below TC increases rapidly in the low magnetic field range for both compounds, and it tends to saturate for Dy2Cu2Cd compound with increasing magnetic field, whereas it is not saturated at 70 kOe for Tm2CuCd compound. To further understand the magnetic transitions, Arrott plots (H/M vs. M2) of Dy2Cu2Cd and Tm2Cu2Cd compounds are shown in Figs 3(b) and 4(b), respectively. According to Banerjee criterion26, the signal (positive and negative) of the slope in Arrott plots has been used to determine the nature of the magnetic phase transition. The negative slopes or inflection points in the Arrott plots often are corresponding to a first order phase transition, whereas the positive slopes are associated to a second order phase transition. By this criterion, neither the inflection points nor negative slopes can be observed in the Arrott plots for Dy2Cu2Cd and Tm2Cu2Cd compounds, indicating a characteristic of the second order (FM-PM) magnetic phase transition.


Excellent magnetocaloric properties in RE 2 Cu 2 Cd ( RE   =   Dy and Tm) compounds and its composite materials
(a) Magnetic field dependence of the magnetization (increasing field only) for Tm2Cu2Cd at some selected temperatures. (b) The plots of H/M versus M2 for Tm2Cu2Cd at some selected temperatures.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f4: (a) Magnetic field dependence of the magnetization (increasing field only) for Tm2Cu2Cd at some selected temperatures. (b) The plots of H/M versus M2 for Tm2Cu2Cd at some selected temperatures.
Mentions: The magnetic isothermal M(H) curves of Dy2Cu2Cd and Tm2Cu2Cd compounds with increasing field around their transition temperatures with increasing magnetic field up to 70 kOe have been measured and some of them are shown in Figs 3(a) and 4(a), respectively. The magnetization below TC increases rapidly in the low magnetic field range for both compounds, and it tends to saturate for Dy2Cu2Cd compound with increasing magnetic field, whereas it is not saturated at 70 kOe for Tm2CuCd compound. To further understand the magnetic transitions, Arrott plots (H/M vs. M2) of Dy2Cu2Cd and Tm2Cu2Cd compounds are shown in Figs 3(b) and 4(b), respectively. According to Banerjee criterion26, the signal (positive and negative) of the slope in Arrott plots has been used to determine the nature of the magnetic phase transition. The negative slopes or inflection points in the Arrott plots often are corresponding to a first order phase transition, whereas the positive slopes are associated to a second order phase transition. By this criterion, neither the inflection points nor negative slopes can be observed in the Arrott plots for Dy2Cu2Cd and Tm2Cu2Cd compounds, indicating a characteristic of the second order (FM-PM) magnetic phase transition.

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.


Related in: MedlinePlus