scholarly journals Effect of gadolinium concentration on temperature change under magnetic field

PLoS ONE ◽  
2019 ◽  
Vol 14 (4) ◽  
pp. e0214910
Author(s):  
Kemal Arda ◽  
Sinan Akay ◽  
Cevat Erisken
Keyword(s):  
Magnetic Field ◽  
Temperature Change ◽  
Gadolinium Concentration

Design and Fabrication of a Magnetocaloric Microcooler

2005 ◽  
Author(s):  
Sangchae Kim ◽  
Bharath Bethala ◽  
Simone Ghirlanda ◽  
Senthil N. Sambandam ◽  
Shekhar Bhansali
Keyword(s):  
Magnetic Field ◽  
Ambient Temperature ◽  
Temperature Change ◽  
Entropy Change ◽  
Temperature Sensors ◽  
Experimental Results ◽  
Maximum Temperature ◽  
Alternative Technology ◽  
Temperature Conditions ◽  
Si Wafer

Magnetocaloric refrigeration is increasingly being explored as an alternative technology for cooling. This paper presents the design and fabrication of a micromachined magnetocaloric cooler. The cooler consists of fluidic microchannels (in a Si wafer), diffused temperature sensors, and a Gd5(Si2Ge2) magnetocaloric refrigeration element. A magnetic field of 1.5 T is applied using an electromagnet to change the entropy of the magnetocaloric element for different ambient temperature conditions ranging from 258 K to 280 K, and the results are discussed. The tests show a maximum temperature change of 7 K on the magnetocaloric element at 258 K. The experimental results co-relate well with the entropy change of the material.

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.

Bulk Transition Elements Based Materials for Magnetic Cooling Application

2011 ◽  
Vol 170 ◽  
pp. 248-252 ◽  
Author(s):  
Mohamed Balli ◽  
Osmann Sari ◽  
L. Zamni ◽  
A. Robert ◽  
J. Forchelet ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Composite Material ◽  
Powder Metallurgy ◽  
Magnetocaloric Effect ◽  
Temperature Change ◽  
Room Temperature ◽  
Test Bench ◽  
Transition Elements ◽  
Magnetic Systems ◽  
Magnetic Cooling

In this paper we investigate the performances of two bulk magnetocaloric refrigerants based on La(Fe,Co)13-xSix and prepared by powder metallurgy. Both materials were developed especially for a magnetic cooling machine. We have determined the magnetocaloric effect in term of temperature change under magnetic field using a test-bench with practical running conditions. ΔT was measured under 2 T and close to room temperature range. The obtained results will be compared with those of some reference materials reported in the literature. In addition, a composite material based on La(Fe,Co)13-xSix is proposed for magnetic systems using Ericsson and AMR cycles for refrigeration close to room temperature.

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.

Design of a Magnetic Cooling Device Using Gadolinium Alloy and Permanent Magnets

2016 ◽  
Author(s):  
Amanie N. Abdelmessih ◽  
Paul W. Bartholomae ◽  
Matthew L. Casillas ◽  
Rocky E. DeLyon ◽  
Joshua F. Flaherty ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetocaloric Effect ◽  
Temperature Change ◽  
Permanent Magnets ◽  
Operating Cost ◽  
Heat Pumps ◽  
Maximum Temperature ◽  
Working Fluid ◽  
Vapor Compression ◽  
Magnetic Cooling

Traditionally, heat pumps and refrigerators utilize the vapor compression cycle to achieve cooling. These vapor compression cycles use hydrochlorofluorocarbons (R134a) as the cycle’s working fluid. This refrigerant contributes to global warming and is expected to be phased out. Consequently, new refrigerants as well as new refrigeration methods need to be developed. The research detailed in this article attempts to implement the magnetocaloric effect of gadolinium alloy in a designed apparatus to lower the temperature of air. Gadolinium alloy has a noticeable magnetocaloric effect within a strong magnetic field (5 T). This research is aimed at producing a noticeable temperature change (2–3 °C) in a relatively smaller magnetic field (1 T) produced with permanent magnets. This work tests the feasibility of magnetic cooling by introducing the design of a magnetic cooling apparatus, using Gadolinium alloy (Gd5Si2Ge2). Small pebbles were used as opposed to a solid plate in order to have an increased surface area to enhance the convection heat transfer process. Permanent magnets were used in the apparatus, to decrease the operating cost. The maximum temperature change encountered in the heat exchanger of the apparatus built was 2.3 °C in a 1 T magnetic field.

Magnetic field induced temperature change in mice

1984 ◽  
Vol 71 (2) ◽  
pp. 100-101 ◽  
Author(s):  
D. Sperber ◽  
R. Oldenbourg ◽  
K. Dransfeld
Keyword(s):  
Magnetic Field ◽  
Temperature Change

scholarly journals Field induced crossover in critical behaviour and direct measurement of the magnetocaloric properties of La0.4Pr0.3Ca0.1Sr0.2MnO3

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sagar Ghorai ◽  
Ridha Skini ◽  
Daniel Hedlund ◽  
Petter Ström ◽  
Peter Svedlindh
Keyword(s):  
Magnetic Field ◽  
Temperature Change ◽  
Room Temperature ◽  
Ion Beam ◽  
Mean Field ◽  
Critical Behaviour ◽  
Potential Candidate ◽  
Ferromagnetic Transition ◽  
X Ray ◽  
Lattice Distortions

Abstract La0.4Pr0.3Ca0.1Sr0.2MnO3 has been investigated as a potential candidate for room temperature magnetic refrigeration. Results from X-ray powder diffraction reveal an orthorhombic structure with Pnma space group. The electronic and chemical properties have been confirmed by X-ray photoelectron spectroscopy and ion-beam analysis. A second-order paramagnetic to ferromagnetic transition was observed near room temperature (289 K), with a mean-field like critical behaviour at low field and a tricritical mean-field like behaviour at high field. The field induced crossover in critical behaviour is a consequence of the system being close to a first-order magnetic transition in combination with a magnetic field induced suppression of local lattice distortions. The lattice distortions consist of interconnected and weakly distorted pairs of Mn-ions, where each pair shares an electron and a hole, dispersed by large Jahn–Teller distortions at Mn3+ lattice sites. A comparatively high value of the isothermal entropy-change (3.08 J/kg-K at 2 T) is observed and the direct measurements of the adiabatic temperature change reveal a temperature change of 1.5 K for a magnetic field change of 1.9 T.

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