Heat pump cycles based on the AF–F transition in Fe–Rh alloys induced by tensile stress

Annaorazov, M.P.; Никитин, С.А.; Tyurin, A.L.; Akopyan, S.A.; Myndyev, R.W.

doi:10.1016/s0140-7007(02)00028-2

Cited by 8 publications

(5 citation statements)

References 5 publications

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“…It is possible to define two types of COP for materials instead of heat pumps. The first type of material COP is defined for a specific refrigeration cycle, and therefore represents an upper bound on the performance of a putative device exploiting that cycle 54,109 . A value of 30 for this type of materials COP was reported 109 for eC effects in Fe 49 Rh 51 when T h -T c = 5 K, falling to 20 when T h -T c = 10 K. The second type of materials COP compares reversible isothermal heat Q with the corresponding work W done by the driving field 80,110 .…”

Section: Prototypes and Applicationsmentioning

confidence: 99%

“…The first type of material COP is defined for a specific refrigeration cycle, and therefore represents an upper bound on the performance of a putative device exploiting that cycle 54,109 . A value of 30 for this type of materials COP was reported 109 for eC effects in Fe 49 Rh 51 when T h -T c = 5 K, falling to 20 when T h -T c = 10 K. The second type of materials COP compares reversible isothermal heat Q with the corresponding work W done by the driving field 80,110 . We will refer to this as a materials efficiency 80 W Q /   rather than a COP 36,110 , to avoid the possibility of false comparison with the Carnot efficiency that bounds device COP.…”

Section: Prototypes and Applicationsmentioning

confidence: 99%

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Caloric materials near ferroic phase transitions

2014

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A magnetically, electrically or mechanically responsive material can undergo significant thermal changes near a ferroic phase transition when its order parameter is modified by the conjugate applied field. The resulting magnetocaloric, electrocaloric and mechanocaloric (elastocaloric or barocaloric) effects are compared here in terms of history, experimental method, performance and prospective cooling applications.

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Section: Prototypes and Applicationsmentioning

confidence: 99%

Section: Prototypes and Applicationsmentioning

confidence: 99%

Caloric materials near ferroic phase transitions

2014

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“…( 1) we obtain ∆S(T cP' ) = ∆S(T c0 ) + ∆C ln(T cP' /T c0 ). Similar calculations for the case of an arbitrary pressure give the result: ∆S(T cP ) = ∆S(T c0 ) + ∆C ln(T cP /T c0 ) (5) Since T cP' -T s = ∆T SF and by using Eq. ( 3) we get T cP' = T s .…”

Section: Model S-t Diagram For Ferh Alloy In Vicinity Of the F-af Tra...mentioning

confidence: 65%

“…On the other hand, the interest can be interpreted by a large change of properties of these alloys during the transition, which could be used in creation sensors/actuators [3,4]. The heat pump cycles based on inducement of the AF-F transition in FeRh alloys by tensile stress and magnetic field, were discussed [5,6]. Since this transition can be induced by pressure as well [7], it may be used for construction of combined heat pump cycles with sign-changing mechanical load of the alloy, which may be useful, for instance, for broadening of the cycles' temperature range.…”

Section: Introductionmentioning

confidence: 99%

Heat Pumping Scheme Based on Inducement of the F-AF Transition in FeRh by Pressure

Rodionov

Rodionova

Annaorazov

2015

SSP

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On the base of the model S–T projection of S–T–P surface for FeRh alloy one of the possible of the heat pump cycles type is drawn up: with acquisition by the alloy the heat from external heat source. Corresponding efficiency of these cycle as functions of temperature at various differences between initial and final temperatures (permanent thermal load ΔT) and as a function of pressure at various differences between initial and final temperatures are analyzed. It is found, particularly, that within the temperature range (320 – 370) K and pressure range (0.4 – 1.0)∙109 Pa efficiency of the heat-pump cycles takes the values from the interval from 30 to 35. These values are comparable to those found recently with using the tensile stress up to ψ = 1∙109 Pa and with using the magnetic field up to H = 2∙106 A/m.

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“…The idea to use this material in magnetic refrigerators was first proposed by [15]. Later on discussion about the creation of a magnetic refrigerator which employs the 1 st order AFM-FM transition were published [16,17].…”

Section: Introductionmentioning

confidence: 99%

Peculiarities of the magnetocaloric effect in FeRh-based alloys in the vicinity of the first order magnetic phase transition

et al. 2018

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Medical applications of magnetocaloric effect (MCE) require possibility for precision shift of a temperature of the magnetic phase transition at the same MCE value and minimize irreversibility. Thus, detail dynamic MCE investigation of such alloys with non-toxic biocompatible dopants need to be done. In present work, the giant magnetocaloric effect, which is observed in the whole family of Fe-Rh alloys, has been investigated in Pd-doped samples in slowly cycled magnetic fields of up to 1.8 T in magnitude for a range of temperatures, 250 K < T < 350 K. The shift of the ferromagnetic/antiferromagnetic transition temperature down towards room temperature and the decrease in the MCE have been observed in these alloys in comparison with a quasi-equiatomic FeRh alloy. The measurements have also shown an asymmetric behaviour of the first order magnetic phase transition with respect to whether the transition is traversed by heating from lower temperatures or cooling from above. These peculiarities have been explained in the framework of the ab-initio density functional theory-based disordered local moment theory of the MCE. The results have been compared with the those for the non-doped FeRh alloy. Thus features of the first order magnetic phase transition that these alloys have in common have been revealed which enable some predictions to be made appropriate for practical applications.

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Heat pump cycles based on the AF–F transition in Fe–Rh alloys induced by tensile stress

Cited by 8 publications

References 5 publications

Caloric materials near ferroic phase transitions

Caloric materials near ferroic phase transitions

Heat Pumping Scheme Based on Inducement of the F-AF Transition in FeRh by Pressure

Peculiarities of the magnetocaloric effect in FeRh-based alloys in the vicinity of the first order magnetic phase transition

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