scholarly journals Gaudefroyite: a mineral with excellent magnetocaloric effect suitable for liquefying hydrogen

2018 ◽  
Vol 6 (13) ◽  
pp. 5260-5264 ◽  
Author(s):  
Rukang Li ◽  
Guangjing Li ◽  
Colin Greaves

A natural mineral, gaudefroyite, displays excellent low temperature magnetocaloric properties that are suitable for liquefying hydrogen.

2012 ◽  
Vol 1454 ◽  
pp. 63-68 ◽  
Author(s):  
Sayan Chandra ◽  
Anis Biswas ◽  
Subarna Datta ◽  
Barnali Ghosh ◽  
A.K. Raychaudhuri ◽  
...  

ABSTRACTWe have successfully prepared La0.5Sr0.5MnO3nanowires using a novel hydrothermal synthesis process and studied their magnetic and magnetocaloric properties. The system exhibits an inverse magnetocaloric effect (IMCE) around 175 K indicating presence of significant AFM correlation. The MCE study reveals a clear paramagnetic (PM) to ferromagnetic (FM) transition near room temperature (T ~ 325K) which is followed by onset of AFM at lower temperatures. The development of the FM-like magnetic state at low temperature is attributed to the enhanced double exchange (DE) driven ferromagnetism in AFM state as predicted by recent theoretical studies.


RSC Advances ◽  
2015 ◽  
Vol 5 (59) ◽  
pp. 47860-47865 ◽  
Author(s):  
Tapas Paramanik ◽  
Tapas Samanta ◽  
R. Ranganathan ◽  
I. Das

In this report the origin of giant inverse magnetocaloric effect at low temperature region has been studied in cluster glass intermetallic compound Dy5Pd2. In this context the procedure to obtain reversible magnetocaloric effect using Maxwell’s relation has been described.


Author(s):  
В.Б. Чжан ◽  
И.С. Терёшина ◽  
А.А. Курганская ◽  
С.А. Лушников ◽  
В.Н. Вербецкий ◽  
...  

Magnetocaloric properties of compounds Gd(Ni0.98Si0.02), Dy(Ni0.95Si0.05) and their hydrides Gd(Ni0.98Si0.02)H3, Dy(Ni0.95Si0.05)H4 were investigated in the temperature range 2 – 100K. It was found that partial substitution of Ni atoms by Si atoms, as well as subsequent hydrogenation can lead to a significant change in the Curie temperature (TC), the magnetocaloric effect, and the temperature at which the maximum MCE (Tmax) is observed. It is shown that the TC and Tmax of the hydrides are shifted by several degrees to the low temperature region with increasing or maintaining the MCE, which can significantly expand the application of such materials in cryogenic engineering.


Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4399 ◽  
Author(s):  
Karol Szałowski

The paper presents a computational study of the magnetocaloric properties of the V12 polyoxovanadate molecular magnet. The description is restricted to low-temperature range (below approximately 100 K), where the magnetic properties of the system in question can be sufficiently modelled by considering a tetramer that consists of four vanadium ions with spins S=1/2. The discussion is focused on the magnetocaloric effect in the cryogenic range. The exact and numerical diagonalization of the corresponding Hamiltonian is used in order to construct the thermodynamic description within a version of the canonical ensemble. The thermodynamic quantities of interest, such as magnetic entropy, specific heat, entropy change under isothermal magnetization/demagnetization, temperature change under adiabatic magnetization/demagnetization, refrigerant capacity, and magnetic Grüneisen ratio, are calculated and discussed extensively. The importance of two quantum level crossings for the described properties is emphasized. The significant ranges of direct and inverse magnetocaloric effect are predicted. In particular, the maximized inverse magnetocaloric response is found for cryogenic temperatures.


2013 ◽  
Vol 114 (16) ◽  
pp. 163915 ◽  
Author(s):  
L. C. Wang ◽  
Q. Y. Dong ◽  
Z. J. Mo ◽  
Z. Y. Xu ◽  
F. X. Hu ◽  
...  

2003 ◽  
Vol 93 (10) ◽  
pp. 6939-6941 ◽  
Author(s):  
A. M. Gomes ◽  
I. S. Oliveira ◽  
A. P. Guimarães ◽  
A. L. Lima ◽  
P. J. von Ranke

RSC Advances ◽  
2016 ◽  
Vol 6 (79) ◽  
pp. 75562-75569 ◽  
Author(s):  
K. P. Shinde ◽  
S. H. Jang ◽  
M. Ranot ◽  
B. B. Sinha ◽  
J. W. Kim ◽  
...  

The most extensive cooling techniques based on gases have faced environmental problems. The magnetic refrigeration is an alternative technology based on magnetocaloric effect. HoN nanoparticles are good refrigerant material at low temperature.


2021 ◽  
Author(s):  
Jun-Jie Hu ◽  
Yan Peng ◽  
Sui-Jun Liu ◽  
He-Rui Wen

The molecular magnetorefrigerant materials for low-temperature magnetic refrigeration and single-molecule magnets for high-density information storage and quantum computing have received extensive attention from chemists and magnetic experts. Lanthanide ions with...


Crystals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 329 ◽  
Author(s):  
Chengfen Xing ◽  
Hu Zhang ◽  
Kewen Long ◽  
Yaning Xiao ◽  
Hanning Zhang ◽  
...  

The effect of different atomic substitutions at Mn sites on the magnetic and magnetocaloric properties in Ni50Mn35Co2Sn13 alloy has been studied in detail. The substitution of Ni or Co for Mn atoms might lower the Mn content at Sn sites, which would reduce the d-d hybridization between Ni 3d eg states and the 3d states of excess Mn atoms at Sn sites, thus leading to the decrease of martensitic transformation temperature TM in Ni51Mn34Co2Sn13 and Ni50Mn34Co3Sn13 alloys. On the other hand, the substitution of Sn for Mn atoms in Ni50Mn34Co2Sn14 would enhance the p-d covalent hybridization between the main group element (Sn) and the transition metal element (Mn or Ni) due to the increase of Sn content, thus also reducing the TM by stabilizing the parent phase. Due to the reduction of TM, a magnetostructural martensitic transition from FM austenite to weak-magnetic martensite is realized in Ni51Mn34Co2Sn13 and Ni50Mn34Co2Sn14, resulting in a large magnetocaloric effect around room temperature. For a low field change of 3 T, the maximum ∆SM reaches as high as 30.9 J/kg K for Ni50Mn34Co2Sn14. A linear dependence of ΔSM upon μ0H has been found in Ni50Mn34Co2Sn14, and the origin of this linear relationship has been discussed by numerical analysis of Maxwell’s relation.


2015 ◽  
Vol 233-234 ◽  
pp. 238-242 ◽  
Author(s):  
Sergey Taskaev ◽  
Konstantin Skokov ◽  
Dmitriy Karpenkov ◽  
Vladimir V. Khovaylo ◽  
Vasiliy D. Buchelnikov ◽  
...  

In this work we report the results of investigation of the magnetocaloric effect in Gd100-xYx (x= 0, 5, 10, 15) cold rolled ribbons. It is shown that the magnetocaloric effect exists within a wide temperature interval 258-295 K and it is comparable with the magnetocaloric effect observed in bulk samples of pure gadolinium. The value of the magnetocaloric effect in the rolled samples is reduced in comparison with the bulk samples and strongly depends on a degree of plastic deformation. High temperature heat treatment can restore a value of the magnetocaloric effect in the cold rolled ribbons up to initial ones. Thus, cold rolling is proposed to be a promising technique for producing thin forms of magnetocaloric materials for heat exchangers of magnetic cooling devices.


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