Magnetic Properties and Magnetocaloric Effect of Gd3Ni in Crystalline and Amorphous States

2012 ◽  
Vol 190 ◽  
pp. 355-358 ◽  
Author(s):  
D.A. Shishkin ◽  
N.V. Baranov ◽  
A.V. Proshkin ◽  
S.V. Andreev ◽  
A.S. Volegov
Keyword(s):  
Magnetic Field ◽  
Magnetocaloric Effect ◽  
Entropy Change ◽  
Rapid Quenching ◽  
Antiferromagnetic Order ◽  
Cooling Power ◽  
Ferromagnetic Behavior ◽  
Field Change ◽  
Ni Alloy ◽  
Magnetic Field Change

The liquid quenched Gd3Ni alloy is observed to exhibit a ferromagnetic behavior below TC = 117 K unlike crystalline compound having an antiferromagnetic order at T < TN = 99 K. Rapid quenching from the melt results in a considerable enhancement of the magnetocaloric effect in Gd3Ni at low magnetic fields. The maximal value of the isothermal magnetic entropy change at a magnetic field change of 20 kOe for the amorphous Gd3Ni surpasses by more than 8 times the SM value for the polycrystalline counterpart. The relative cooling power for the amorphous Gd3Ni alloy is estimated as 265 J kg-1 and 676 J kg-1 at a magnetic field change of 20 kOe and 50 kOe, respectively.

The Influence of the Purity of Gd on the Magnetocaloric Effect in Gd5Si2-XGe2-XZn2x Alloys

2011 ◽  
Vol 685 ◽  
pp. 311-315
Author(s):  
Zhi Zeng ◽  
Xue Zhen Wang ◽  
Jian Huang ◽  
Jie Xiang ◽  
Xue Ling Hou
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Magnetocaloric Effect ◽  
Curie Point ◽  
Magnetic Entropy Change ◽  
Entropy Change ◽  
Magnetic Entropy ◽  
Field Change ◽  
Magnetic Field Change ◽  
Giant Magnetocaloric Effect

Gd5Si2Ge2-based alloys can exhibit a giant magnetocaloric effect (GMCE) which gives them the potential use in the cooling technologies[1].Through this studies, it can be found that the purity of Gd had a great impact on the magnetocaloric effect in Gd5Si2-xGe2-xZn2x alloys. When 3N Gd used and 2x=0.01, Gd5Si2-xGe2-xZn2x around the curie point of 280k get the maximum magnetic entropy change of 14.0 J/(Kg.K) under the external magnetic field change from 0 to 1T, but when 2N Gd used and 2x=0.05, Gd5Si2-xGe2-xZn2x around the curie point of 284.2k under the external magnetic field change 1T get the maximum magnetic entropy change 6.65 J/(Kg.K).

Magnetocaloric Effect in Ni-Mn-Ga and Ni-Co-Mn-In Heusler Alloys

2009 ◽  
Vol 1200 ◽  
Author(s):  
Vasiliy Buchelnikov ◽  
Sergey Taskaev ◽  
Mikhail Drobosyuk ◽  
Vladimir Sokolovskiy ◽  
Viktor Koledov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetocaloric Effect ◽  
Curie Point ◽  
Direct Method ◽  
Heusler Alloys ◽  
Field Change ◽  
Adiabatic Temperature Change ◽  
Magnetic Field Change ◽  
A Direct Method ◽  
The Magnetic Field

AbstractThe positive magnetocaloric effect (MCE) in the vicinity of the Curie point in Ni2+xMn1-xGa (x=0.33, 0.36, 0.39) Heusler alloys and the negative and positive MCE near the metamagnetostructural (MMS) transition and the Curie point, respectively, in Ni45Co5Mn36.5In13.5 Heusler alloy has been measured by a direct method. For the magnetic field change ΔH = 2 T, the maximal adiabatic temperature change ΔTad at the Curie point in Ni2+xMn1-xGa alloys is larger than 0.6 K. For Ni45Co5Mn36.5In13.5 alloy, the maximal value of ΔTad = 1.68 K (for the same magnetic field change, ΔH = 2 T) is observed at the MMS phase transition temperature.

Refrigerant Capacity and Magnetocaloric Effect on LaFe11.1Co0.8Si1.1BX Alloys

2011 ◽  
Vol 84-85 ◽  
pp. 667-670
Author(s):  
Guo Qiu Xie
Keyword(s):  
Magnetocaloric Effect ◽  
Room Temperature ◽  
Magnetic Entropy Change ◽  
Entropy Change ◽  
Magnetic Entropy ◽  
Field Change ◽  
Refrigerant Capacity ◽  
Structure Phase ◽  
Magnetic Field Change ◽  
Cubic Structure

In this paper, we report on the structure, magnetic properties and magnetocaloric effect in NaZn13-type LaFe11.1Co0.8Si1.1Bxalloys close to room temperature. The stable NaZn13cubic structure phase (space group isFm-3c) can easily obtained by annealing at 1080 °C for 225 hours. The maximal values of magnetic entropy change for LaFe11.1Co0.8Si1.1Bx(x=0.2, 0.25) were found to be 5.3 and 5.9 J/kg K at Curie temperature for a magnetic field change in 0-1.5 T, respectively. The calculated refrigerant capacity for a field change in 0–1.5 T is about 147 and 107 J/kg K, for LaFe11.1Co0.8Si1.1B0.2and LaFe11.1Co0.8Si1.1B0.25respectively, which is as larger as those of Gd(99.3%) alloy

The Magnetocaloric Effect in Ni-Mn-X (X=Ga, in) Heusler Alloys and Manganites with Magnetic Transition close to Room Temperature

2010 ◽  
Vol 168-169 ◽  
pp. 165-168
Author(s):  
Vasiliy D. Buchelnikov ◽  
Mikhail Drobosyuk ◽  
E.A. Smyshlyaev ◽  
O.O. Pavlukhina ◽  
A.V. Andreevskikh ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetocaloric Effect ◽  
Room Temperature ◽  
Direct Method ◽  
Magnetic Transition ◽  
Heusler Alloys ◽  
Field Change ◽  
Adiabatic Temperature Change ◽  
Magnetic Field Change ◽  
The Magnetic Field

The magnetocaloric effect (MCE) in theNi2+xMn1-xGa (x = 0.33, 0.36, 0.39), Ni50Mn25In25, Ni54Mn21Ga18In7, Ni53.5Mn21.5Ga16In9, Ni45Co5Mn36.5In13.5 Heusler alloys and in the La0.7BayCa0.3-yMnO3 (y = 0.12, 0.24, 0.3) manganites at the Curie points have been measured by the direct method. For the magnetic field change H = 2 T, the maximal adiabatic temperature change Tad in the Ni2+xMn1-xGa alloys is larger than 0.6 K. For the Ni50Mn25In25 alloy the maximal value of Tad = 1.51 K (for the same magnetic field change H = 2 T) is observed at the magnetic phase transition temperature.

Magnetic Properties and Magnetocaloric Effect of Nd0.7Gd0.3Mn2Si2 Alloy

2017 ◽  
Vol 1142 ◽  
pp. 47-52 ◽  
Author(s):  
Shi Dong Lin ◽  
Xiao Long Chen ◽  
Jiang Wang ◽  
Chao Fan Zhu ◽  
Mao Hua Rong ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetocaloric Effect ◽  
Physical Property Measurement System ◽  
Physical Property ◽  
Entropy Change ◽  
Spin Reorientation ◽  
Cooling Power ◽  
Field Change ◽  
X Ray Diffraction ◽  
Scanning Calorimetry

In this work, crystal structure, magnetic properties and magnetocaloric effect of Nd0.7Gd0.3Mn2Si2 alloy were studied by X-ray diffraction (XRD), Physical Property Measurement System (PPMS) and Differential Scanning Calorimetry (DSC). Nd0.7Gd0.3Mn2Si2 crystallizes in ThCr2Si2-typed structure with space group I4/mmm, in which the Nd, Gd, Mn and Si atoms occupy 2a (0, 0, 0), 2a (0, 0, 0), 4d (0, 1/2, 1/4) and 4e (0, 0, 0.38261) position, respectively. The Curie temperature (Tc) of Nd0.7Gd0.3Mn2Si2 alloy is 42 K, while the spin reorientation temperature (TSR) is 26 K and the Nel temperature (TN) is 410 K. The Tc and TN were determined using PPMS and DSC, respectively. The maximum value of the magnetic entropy change (-Smax) in the field change of 0-5 T is 11.862 J/kg K, while the value of relative cooling power (RCP) in Nd0.7Gd0.3Mn2Si2 alloy is 69.666 J/kg under the field change of 5 T.

Structure, Magnetic Properties and Magnetocaloric Effect of Dy-Doped CeFe2 Alloys

2013 ◽  
Vol 700 ◽  
pp. 75-78 ◽  
Author(s):  
Wen Jiang Feng ◽  
Ming Gao ◽  
Hao Hua Zhang ◽  
Yan He
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Magnetocaloric Effect ◽  
Phase Structure ◽  
Laves Phase ◽  
Field Change ◽  
Arc Melting ◽  
Magnetic Field Change ◽  
Xrd Patterns ◽  
Curie Temperatures

Ce1-xDyxFe1.9(x = 0, 0.02, 0.05, 0.1) alloys were prepared successfully by means of arc-melting and the following homogenization. XRD patterns show all alloys are indexed as MgCu2-type C15 cubic Laves phase structure. With the Dy substitution of Ce, the Curie temperatures from ferro-to para-magnetism become gradually enlarged. The values of for a magnetic-field change from 0-5 T at 234, 246, 268, 303 K are 31.7, 26.4, 21.8, and 17.2 J kg-1K-1for x = 0, 0.02, 0.05, and 1, respectively.

Direct and Inverse Magnetocaloric Effect in Ni1.81Mn1.64In0.55 Multifunctional Heusler Alloy

2015 ◽  
Vol 233-234 ◽  
pp. 183-186 ◽  
Author(s):  
Rafael Fayzullin ◽  
Vasiliy D. Buchelnikov ◽  
Mikhail Drobosyuk ◽  
Alexey Mashirov ◽  
Alexander Kamantsev ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Magnetocaloric Effect ◽  
Heusler Alloy ◽  
Direct Method ◽  
Field Change ◽  
Adiabatic Temperature Change ◽  
Phase Transition Temperatures ◽  
Magnetic Field Change ◽  
The Magnetic Field

The magnetocaloric effect (MCE) in Ni1.81Mn1.64In0.55 Heusler alloy has been measured by the direct method. The field dependences of the magnetization were obtained. The phase transition temperatures were determined. The maximal adiabatic temperature change ΔTad near the Curie temperature is 1.8 K under the magnetic field change ∆H = 18 kOe. The inverse MCE (∆Tad = -3.72 K) in the same field change takes place near the temperature of martensitic transformation.

scholarly journals Reversibility of the Magnetocaloric Effect in the Bean-Rodbell Model

2021 ◽  
Vol 7 (5) ◽  
pp. 60
Author(s):  
Luis M. Moreno-Ramírez ◽  
Victorino Franco
Keyword(s):  
Magnetic Field ◽  
Thermal Hysteresis ◽  
Entropy Change ◽  
Second Order ◽  
Zero Field ◽  
First Order ◽  
Magnetic Field Change ◽  
Magnetocaloric Materials ◽  
Moderate Magnetic Field ◽  
The Magnetic Field

The applicability of magnetocaloric materials is limited by irreversibility. In this work, we evaluate the reversible magnetocaloric response associated with magnetoelastic transitions in the framework of the Bean-Rodbell model. This model allows the description of both second- and first-order magnetoelastic transitions by the modification of the η parameter (η<1 for second-order and η>1 for first-order ones). The response is quantified via the Temperature-averaged Entropy Change (TEC), which has been shown to be an easy and effective figure of merit for magnetocaloric materials. A strong magnetic field dependence of TEC is found for first-order transitions, having a significant increase when the magnetic field is large enough to overcome the thermal hysteresis of the material observed at zero field. This field value, as well as the magnetic field evolution of the transition temperature, strongly depend on the atomic magnetic moment of the material. For a moderate magnetic field change of 2 T, first-order transitions with η≈1.3−1.8 have better TEC than those corresponding to stronger first-order transitions and even second-order ones.

scholarly journals Magnetic Properties and Magnetocaloric Effect in Gd100-xCox Thin Films

Crystals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 278 ◽  
Author(s):  
Mohamed Tadout ◽  
Charles-Henri Lambert ◽  
Mohammed El Hadri ◽  
Abdelilah Benyoussef ◽  
Mohammed Hamedoun ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetocaloric Effect ◽  
Magnetic Entropy Change ◽  
Entropy Change ◽  
Magnetic Thin Films ◽  
Critical Parameters ◽  
Cooling Power ◽  
Magnetocaloric Properties ◽  
Co Concentration ◽  
Key Parameter

We investigated the magnetic and magnetocaloric properties of Gd100-xCox ( x = 40 to 56) thin films fabricated by the sputtering technique. Under an applied field change Δ H = 20 kOe , the magnetic entropy change ( Δ S m ) decreases from 2.64 Jkg−1K−1 for x = 44 to about 1.27 Jkg−1K−1 for x = 56. Increasing the Co concentration from x = 40 to 56 shifts the Curie temperature of Gd100-xCox ( x = 40 to 56) thin films from 180 K toward 337 K. Moreover, we extracted the values of critical parameters Tc, β, γ, and δ by using the modified Arrott plot methods. The results indicate the presence of a long-range ferromagnetic order. More importantly, we showed that the relative cooling power (RCP), which is a key parameter in magnetic refrigeration applications, is strongly enhanced by changing the Co concentration in the Gd100-xCox thin films. Our findings help pave the way toward the enhancement of the magnetocaloric effect in magnetic thin films.

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