Influence of thermal conductivity on the dynamic response of magnetocaloric materials

Porcari, G.; Morrison, Kelly; Cugini, F.; Turcaud, J.A.; Guillou, F.; Berenov, A.; Dijk, N.H. van; Brueck, E.; Cohen, L. F.; Solzi, M.

doi:10.1016/j.ijrefrig.2015.06.028

Cited by 24 publications

(26 citation statements)

References 41 publications

(44 reference statements)

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“…The sintered sample shows a time constant of approximately 100 ms. This can be explained by the time needed to decrease the field or rather move the sample out of the region with high field and the small time delay of the temperature sensor due to its heat capacity . The time constant of the composite (sample A) is more than two times larger than the time constant of the sintered sample.…”

Section: Resultsmentioning

confidence: 99%

“…A detailed description of the setup can be found in Ref. . In the reported experiments, two parts of the same sample were overlapping to increase its thermal mass.…”

Section: Methodsmentioning

confidence: 99%

“…This, and the limited machinability of the brittle intermetallic material, led to the use of composites in which the active magnetocaloric particles are embedded into an either metallic or polymer matrix . The addition of a passive material that takes up heat and cold but, unlike the magnetocaloric particles, does not produce any, leads to a decrease in the maximum adiabatic temperature changes (Δ T ad ) observed for the composite . Furthermore, due to an additional heat transfer process from the active particles to the passive matrix, the characteristic timescale for heat transfer τ is increased.…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, due to an additional heat transfer process from the active particles to the passive matrix, the characteristic timescale for heat transfer τ is increased. The last two points (decrease of Δ T ad and increase of τ ) have been observed for a purely two‐phase system consisting of the particle and the matrix . The interfacial boundary, and therefore also its resistance, have been neglected previously.…”

Section: Introductionmentioning

confidence: 99%

“…[7,8] Thea dditiono fa passive materialt hat takes up heat and cold but, unlike the magnetocaloric particles,does not produce any,leads to adecrease in the maximum adiabatic temperature changes (DT ad )o bserved for the composite. [9] Furthermore, due to an additional heat transfer process from the active particles to the passive matrix, the characteristic timescale for heat transfer t is increased. Thel ast two points (decrease of DT ad and increaseo ft)h ave been observed for ap urely two-phase system consisting of the particle and the matrix.…”

Section: Introductionmentioning

confidence: 99%

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Interfacial Thermal Resistance in Magnetocaloric Epoxy‐Bonded La‐Fe‐Co‐Si Composites

et al. 2018

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Magnetocaloric composites made from La−Fe−Co−Si particles and an epoxy binder matrix exhibit mechanical stability and good magnetocaloric properties, but also a large characteristic time for thermal transport. Here, the origin of this large time constant is examined by comparing two measurement techniques, direct and contactless, to finite‐element simulations based on a tomographic dataset of the sample. The combination of the low thermal conductivity of the epoxy matrix and a thermal resistance at the interface between epoxy and La−Fe−Co−Si is shown to be in good agreement in simulations and experiments. The findings help to disentangle the role of the thermal conductivity and the interfacial thermal resistance for the heat flow in magnetocaloric composites. It is shown that the low thermal conductivity of the epoxy alone cannot explain the large time constant and possibilities for using the interfacial thermal resistance to tailor anisotropic thermal conductivity for directional heat transfer in magnetocaloric composites are presented.

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Section: Resultsmentioning

confidence: 99%

“…A detailed description of the setup can be found in Ref. . In the reported experiments, two parts of the same sample were overlapping to increase its thermal mass.…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Interfacial Thermal Resistance in Magnetocaloric Epoxy‐Bonded La‐Fe‐Co‐Si Composites

et al. 2018

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Graphene‐Based Magnetocaloric Composites for Energy Conversion

et al. 2022

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Herein, a simple, versatile, and cost‐effective method to fabricate innovative thermal conductive magnetocaloric (MC) composites, which offers a smart solution to manufacture active elements with desired geometries, overcoming the current thermal and mechanical limits of the most studied MC materials, is presented. The composite is prepared by embedding powder of a MC material in an epoxy matrix enriched with a graphene‐based material, obtained by thermal exfoliation of graphite oxide. The graphene‐enriched composite shows a significant improvement of the MC time response to the magnetic field, due to the formation of a 3D network that bridges the MC particles and reduces the metal–matrix contact resistance, thus creating a percolation path for an efficient heat transfer. Because of the simplicity and scalability of the preparation method and the great enhancement in response time, these new functional composites represent an important step for the effective application of MC materials in thermomagnetic devices for the energy conversion.

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Outstanding Comprehensive Performance of La(Fe, Si)₁₃H_y/In Composite with Durable Service Life for Magnetic Refrigeration

Wang

Zhang

Liu

et al. 2018

Adv Elect Materials

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temperature, has become a promisingly alternative technology to the existing vapor-compression refrigeration due to its energy efficiency and environment friendly. [4][5][6] As the core part of magnetic refrigeration, the comprehensive performance including MCE, thermal conductivity (λ), preparation and fabrication, corrosion resistance, and thermal and magnetic field cycling stabilities for magnetocaloric materials greatly affect the performance of the magnetic refrigerator. [7,8] Pure Gd, as the benchmark magnetic refrigerant, is commonly used in the active magnetic regenerator prototypes. [9,10] In particular, Gd metal could be produced into different shapes due to its good mechanical properties, such as thin plate, sphere, and microwire, and it has been demonstrated that microwire is more desirable for realizing a higher cooling performance. [11][12][13][14][15][16] However, Gd metal also has its disadvantages such as relatively low magnetic entropy change (ΔS M ), limited availability, and expensive price that hinder its large-scale commercialization. Therefore, a great number of magnetic materials with large MCE around room temperature have been extensively explored in the past decades. [2,6,[17][18][19][20] Unfortunately, although these new materials exhibit much better MCE than that of Gd, they still have severe shortcomings such as hard preparation Magnetic refrigeration based on magnetocaloric effect (MCE) has become a promisingly alternative technology to the conventional vapor-compression refrigeration. A great number of magnetic materials have been reported to exhibit larger MCE than that of the benchmark magnetic refrigerant Gd.However, these materials still have severe shortcomings on the "Non-MCE" properties, such as hard preparation and fabrication, low thermal conductivity λ, and poor corrosion resistance and cycling stabilities, which hinder the practical application of these materials. In this paper, a novel La(Fe, Si) 13 H y / In composite which is prepared by a readily available hot pressing method is demonstrated to exhibit an outstanding comprehensive performance with durable service life in various aspects. Noteworthily, the ΔS M does not decrease but increases with increasing nonmagnetic In metal. This advantageous anomaly is related to the strengthening of the first-order itinerant electron metamagnetic transition induced by residual compression stress and surrounded constraints in the composite. The present results make La(Fe, Si) 13 H y /In composite the most attractive alternative to Gd for magnetic refrigeration. Moreover, this work also provides a feasible way to solve the serious issues toward applications for La(Fe, Si) 13 -based materials and other brittle magnetocaloric materials.

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Influence of thermal conductivity on the dynamic response of magnetocaloric materials

Cited by 24 publications

References 41 publications

Interfacial Thermal Resistance in Magnetocaloric Epoxy‐Bonded La‐Fe‐Co‐Si Composites

Interfacial Thermal Resistance in Magnetocaloric Epoxy‐Bonded La‐Fe‐Co‐Si Composites

Graphene‐Based Magnetocaloric Composites for Energy Conversion

Outstanding Comprehensive Performance of La(Fe, Si)₁₃H_y/In Composite with Durable Service Life for Magnetic Refrigeration

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Influence of thermal conductivity on the dynamic response of magnetocaloric materials

Cited by 24 publications

References 41 publications

Interfacial Thermal Resistance in Magnetocaloric Epoxy‐Bonded La‐Fe‐Co‐Si Composites

Interfacial Thermal Resistance in Magnetocaloric Epoxy‐Bonded La‐Fe‐Co‐Si Composites

Graphene‐Based Magnetocaloric Composites for Energy Conversion

Outstanding Comprehensive Performance of La(Fe, Si)13Hy/In Composite with Durable Service Life for Magnetic Refrigeration

Contact Info

Product

Resources

About

Outstanding Comprehensive Performance of La(Fe, Si)₁₃H_y/In Composite with Durable Service Life for Magnetic Refrigeration