Simple Set-Up for Adiabatic Measurements of Magnetocaloric Effect

2015 ◽  
Vol 644 ◽  
pp. 215-218 ◽  
Author(s):  
P. Álvarez-Alonso ◽  
J. López-García ◽  
G. Daniel-Perez ◽  
D. Salazar ◽  
P. Lázpita ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetocaloric Effect ◽  
Temperature Change ◽  
Heusler Alloy ◽  
Cost Effective ◽  
Adiabatic Temperature ◽  
Magnetic Phase Transitions ◽  
Adiabatic Temperature Change ◽  
Set Up ◽  
The Magnetic Field

We present a cost-effective and robust set-up designed to measure directly the magnetic field-induced adiabatic temperature change. The system uses a piston to introduce/remove the sample to/from the magnetic field (μ0∆His up to 1.7T) created by an ordinary electromagnet. The temperature of the sample is controlled by a double pipe heat exchanger operating by the electrical heater and air flow circulation from a Dewar with liquid nitrogen to the sample holder assembly.We have measured the adiabatic temperature change, ΔTad, of two polycrystalline samples: Gd and Ni50Mn35In15Heusler alloy. At the second-order magnetic phase transitions (18oC for Gd and 42oC for Ni50Mn35In15), ΔTadunder μ0∆H=1.7T are 3.8±0.1oC for Gd and 1.9±0.1oC for Ni50Mn35In15. The Heusler alloy shows an inverse magnetocaloric effect: ΔTadis-1.5±0.1oC on cooling and-1.6±0.1oC on heating at the martensitic transformation temperatures of ~24oC and ~29oC, respectively.

scholarly journals Магнитокалорический эффект в сплаве Fe-=SUB=-49-=/SUB=-Rh-=SUB=-51-=/SUB=- в импульсных магнитных полях до 50 T

2020 ◽  
Vol 62 (1) ◽  
pp. 117
Author(s):  
А.П. Каманцев ◽  
А.А. Амиров ◽  
Ю.С. Кошкидько ◽  
К. Салазар Мехиа ◽  
А.В. Маширов ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Temperature Change ◽  
Initial Temperature ◽  
Adiabatic Temperature ◽  
Ferromagnetic Phase ◽  
Pulsed Magnetic Fields ◽  
Absolute Value ◽  
Adiabatic Temperature Change ◽  
The Absolute ◽  
The Magnetic Field

The direct magnetocaloric effect (MCE) was measured in pulsed magnetic fields up to 50 T in the Fe49Rh51 alloy. At different initial temperatures in the metamagnetic phase transition with an increase in the field up to 20 T, a reverse MCE ∆T ≈ -8 K is observed, while a further increase in the field to 50 T results in a decrease in the absolute value of the adiabatic temperature change by ~ 1 K, which is connected with direct MCE and indicates a complete transition of the sample into the ferromagnetic phase. The maximum of the absolute value of the adiabatic temperature change |∆Т| = 9.8 K with a decrease in the magnetic field of 6 T on initial temperature of 310 K was observed.

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.

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.

scholarly journals Tunable Magnetocaloric Properties of Gd-Based Alloys by Adding Tb and Doping Fe Elements

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2877 ◽  
Author(s):  
Lingfeng Xu ◽  
Chengyuan Qian ◽  
Yongchang Ai ◽  
Tong Su ◽  
Xueling Hou
Keyword(s):  
Magnetic Field ◽  
Curie Temperature ◽  
Temperature Change ◽  
Indirect Measurement ◽  
Adiabatic Temperature ◽  
Doping Content ◽  
Adiabatic Temperature Change ◽  
Magnetocaloric Properties ◽  
Capacity Calculation ◽  
Low Magnetic Field

In this paper, the magnetocaloric properties of Gd1−xTbx alloys were studied and the optimum composition was determined to be Gd0.73Tb0.27. On the basis of Gd0.73Tb0.27, the influence of different Fe-doping content was discussed and the effect of heat treatment was also investigated. The adiabatic temperature change (ΔTad) obtained by the direct measurement method (under a low magnetic field of 1.2 T) and specific heat capacity calculation method (indirect measurement) was used to characterize the magnetocaloric properties of Gd1−xTbx (x = 0~0.4) and (Gd0.73Tb0.27)1−yFey (y = 0~0.15), and the isothermal magnetic entropy (ΔSM) was also used as a reference parameter for evaluating the magnetocaloric properties of samples together with ΔTad. In Gd1−xTbx alloys, the Curie temperature (Tc) decreased from 293 K (x = 0) to 257 K (x = 0.4) with increasing Tb content, and the Gd0.73Tb0.27 alloy obtained the best adiabatic temperature change, which was ~3.5 K in a magnetic field up to 1.2 T (Tc = 276 K). When the doping content of Fe increased from y = 0 to y = 0.15, the Tc of (Gd0.73Tb0.27)1−yFey (y = 0~0.15) alloys increased significantly from 276 K (y = 0) to 281 K (y = 0.15), and a good magnetocaloric effect was maintained. The annealing of alloys (Gd0.73Tb0.27)1−yFey (y = 0~0.15) at 1073 K for 10 h resulted in an average increase of 0.3 K in the maximum adiabatic temperature change and a slight increase in Tc. This study is of great significance for the study of magnetic refrigeration materials with adjustable Curie temperature in a low magnetic field.

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.

Adiabatic Temperature Change in Metamagnetic Ni(Co)-Mn-Al Heusler Alloys

2013 ◽  
Vol 738-739 ◽  
pp. 446-450 ◽  
Author(s):  
Vladimir Khovaylo ◽  
Maria Lyange ◽  
Konstantin Skokov ◽  
Oliver Gutfleisch ◽  
Ratnamala Chatterjee ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Experimental Study ◽  
Shape Memory Alloy ◽  
Temperature Change ◽  
Heusler Alloys ◽  
Alloy System ◽  
Adiabatic Temperature ◽  
Adiabatic Temperature Change ◽  
Measurement Protocol ◽  
Magnetocaloric Properties

Two representatives of Ni(Co)-Mn-Al metamagnetic shape memory alloy system, Ni45Co5Mn31Al19 and Ni35Co15Mn35Al15, have been studied with respect to their magnetocaloric properties. Experimental study of the magnetocaloric effect by a direct measurement of the adiabatic temperature change ΔTad revealed that in both the samples ΔTad depends on the measurement protocol as well as on the magnetic prehistory of the samples. For the applied magnetic field µ0H = 1.93 T, the largest adiabatic temperature change, |ΔTad| ~ 0.7 K, has been observed in the Ni35Co15Mn35Al15 sample at T = 464 K.

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