Multicalorics

Moya, Xavier; Phan, Manh‐Huong; Srikanth, H.; Albertini, F.

doi:10.1063/5.0039106

Cited by 6 publications

(5 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Unidirectional heat flow in an all-solid electrocaloric heat pump without moving parts has also been postulated [32], but the calculated cooling power (and temperature span) was much lower than that of a conventional electrocaloric heat pump [28]. Another approach to combine at least two caloric effects (multicalorics [33]) is also beyond the scope of this work.…”

Section: State-of-the-artmentioning

confidence: 96%

Spatio-temporal solid-state electrocaloric effect exceeding twice the adiabatic temperature change

Moench

Bartholomé

2023

J. Phys. Energy

View full text Add to dashboard Cite

In an all-solid-state electrocaloric arrangement, an absolute temperature change which exceeds twice the electrocaloric adiabatic temperature change is locally realized, using just the distributed thermal capacitances and resistances and spatio-temporal distributed electric ﬁeld control. First, simulations demonstrate surface temperature changes up to four times (400%) the electrocaloric adiabatic temperature change for several implementations of all-solid state distributed element conﬁgurations. Then, experimentally, an all-solid-state assembly is built from commercial electrocaloric capacitors with two independently-controlled parts, and the measured surface temperature change was 223% of the adiabatic electrocaloric temperature change, which clearly exceeds twice the adiabatic temperature change and veriﬁes the practical feasibility of the approach. This allows a signiﬁcant increase of the maximum temperature diﬀerence per stage in cascaded and thermal switch-based electrocaloric heat pumps, which was previously limited by the adiabatic electrocaloric temperature change (100%) under no-load conditions. Distributed thermal element simulations provide insight in the spatio-temporal temperatures within the all-solid-state electrocaloric element. Since only the distributed thermal capacitance and resistance is used to boost the temperature change, the maximum absolute temperature change occurs only in parts of the all-solid-state element, for example close to the surfaces. A trade-oﬀ of the approach is that the required electrocaloric capacitance increases more than the gained boost of the absolute temperature change, reducing the power density and electrical eﬃciency in heat pump systems. Nevertheless, the proposed approach enables to simplify electrocaloric heat pumps or to increasing the achievable temperature span, and might also improve other electrocaloric applications.

show abstract

Section: State-of-the-artmentioning

confidence: 96%

Spatio-temporal solid-state electrocaloric effect exceeding twice the adiabatic temperature change

Moench

Bartholomé

2023

J. Phys. Energy

View full text Add to dashboard Cite

show abstract

“…In addition to the magnetocaloric, there are also other caloric effects such as the barocaloric, elastocaloric or electrocaloric effects [76][77][78][79][80][81]. Here, various external stimuli trigger a temperature and entropy change in the material.…”

Section: Multicaloric Measurementsmentioning

confidence: 99%

On the high-field characterization of magnetocaloric materials using pulsed magnetic fields

Salazar Mejía,

Niehoff,

Straßheim

et al. 2023

J. Phys. Energy

View full text Add to dashboard Cite

Magnetic refrigeration is a highly active field of research. The recent studies in materials and methods for hydrogen liquefaction and innovative techniques based on multicaloric materials have significantly expanded the scope of the field. For this reason, the proper characterization of materials is now more crucial than ever. This makes it necessary to determine the magnetocaloric and other physical properties under various stimuli such as magnetic fields and mechanical loads. In this work, we present an overview of the characterization techniques established at the Dresden High Magnetic Field Laboratory in recent years, which specializes in using pulsed magnetic fields. The short duration of magnetic-field pulses, lasting only some ten milliseconds, simplifies the process of ensuring adiabatic conditions for the determination of temperature changes, ∆Tad. The possibility to measure in the temperature range from 10 to 400 K allows us to study magnetocaloric materials for both room-temperature applications and gas liquefaction. With magnetic-field strengths of up to 50 T, almost every first-order material can be transformed completely. The high field-change rates allow us to observe dynamic effects of phase transitions driven by nucleation and growth as well. We discuss the experimental challenges and advantages of the investigation method using pulsed magnetic fields. We summarize examples for some of the most important material classes including Gd, Laves phases, La-Fe-Si, Mn-Fe-P-Si, Heusler alloys and Fe-Rh. Further, we present the recent developments in simultaneous measurements of temperature change, strain, and magnetization, and introduce a technique to characterize multicaloric materials under applied magnetic field and uniaxial load. We conclude by demonstrating how the use of pulsed fields opens the door to new magnetic-refrigeration principles based on multicalorics and the “exploiting-hysteresis” approach.

show abstract

“…Furthermore, the smart design of magnetocaloric materials with functional polymers enables the development of multifunctional composites exhibiting large responses to different external stimuli (including magnetic, electric, and pressure fields) and cross-coupling effects, such as magnetoelectric coupling in multiple systems. − Within the context of caloric applications, these systems are known as multicaloric composites. ,− The application of multicaloric materials in prototype devices has already enabled reaching higher cooling power and efficiency . A prime example of the latter is the multicaloric heat pump design proposed by Gottschall et al that makes use of the barocaloric and magnetocaloric effects by applying/removing uniaxial stress and magnetic fields, respectively, in such a way that hysteresis is further exploited …”

Section: Introductionmentioning

confidence: 99%

“… 33 − 35 Within the context of caloric applications, these systems are known as multicaloric composites. 34 , 36 − 38 The application of multicaloric materials in prototype devices has already enabled reaching higher cooling power 39 and efficiency. 40 A prime example of the latter is the multicaloric heat pump design proposed by Gottschall et al that makes use of the barocaloric and magnetocaloric effects by applying/removing uniaxial stress and magnetic fields, respectively, in such a way that hysteresis is further exploited.…”

Section: Introductionmentioning

confidence: 99%

Flexible Magnetocaloric Fiber Mats for Room-Temperature Energy Applications

Bayzi Isfahani,

Coondoo,

Bdikin

et al. 2024

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

Currently, magnetocaloric refrigeration technologies are emerging as ecofriendly and more energy-efficient alternatives to conventional expansion−compression systems. However, major challenges remain. A particular concern is the mechanical properties of magnetocaloric materials, namely, their fatigue under cycling and difficulty in processing and shaping. Nevertheless, in the past few years, using multistimuli thermodynamic cycles with multicaloric refrigerants has led to higher heat-pumping efficiencies. To address simultaneously the challenges and develop a multicaloric material, in this work, we have prepared magnetocaloric-based flexible composite mats composed of micrometric electroactive (EA) polyvinylidene fluoride (PVDF) fibers with embedded magnetocaloric/strictive La(Fe,Si) 13 particles by the simple and cost-effective electrospinning technique. The composite's structural characterization, using X-ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) spectroscopy, and measurements of the local-scale piezoresponse, revealed a cubic NaZn 13 -type structure of the La(Fe,Si) 13 phase and the formation of the dominant polar β-phase of the PVDF polymer. The PVDF-La(Fe,Si) 13 composite showed an enhancement of the longitudinal piezoelectric coefficient (effective d 33 ) (−11.01 pm/V) compared with the single PVDF fiber matrix (−9.36 pm/V). The main magnetic properties of La(Fe,Si) 13 powder were retained in the PVDF-La(Fe,Si) 13 composite, including its giant magnetocaloric effect. By retaining the unique magnetic properties of La(Fe,Si) 13 embedded in the electroactive piezoelectric polymer fiber mats, we have designed a flexible, easily shapeable, and multifunctional composite enabling its potential application in multicaloric heat-pumping devices and other sensing and actuating devices.

show abstract

Multicalorics

Cited by 6 publications

References 37 publications

Spatio-temporal solid-state electrocaloric effect exceeding twice the adiabatic temperature change

Spatio-temporal solid-state electrocaloric effect exceeding twice the adiabatic temperature change

On the high-field characterization of magnetocaloric materials using pulsed magnetic fields

Flexible Magnetocaloric Fiber Mats for Room-Temperature Energy Applications

Contact Info

Product

Resources

About