Design of Active Magnetic Regenerative Stage Interfacing to a G-M Cryocooler

Zimm, C. B.; Jastrab, A. G.; Johnson, J.W.

doi:10.1007/978-1-4757-9888-3_65

Cited by 4 publications

(3 citation statements)

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“…Discovery of the giant magnetocaloric effect in Gd 5 Si 2 Ge 2 , followed by a successful test of a rotary magnetic refrigerator, , showed that the magnetocaloric effect may be beneficially utilized for room-temperature refrigeration and air conditioning. The unique feature which makes Gd 5 Si 2 Ge 2 and other materials, like MnFeP 1- x As x , suitable for practical applications is an intrinsic coupling between a first-order structural transition and ferromagnetic ordering. , As a result, the entropy change is significantly increased (nearly doubled in Gd 5 Si 2 Ge 2 for Δ H = 0−5 T) and the magneto-structural transformation yields a large temperature response to magnetic field .…”

Section: Introductionmentioning

confidence: 99%

Gd₅Si_4−xP_x: Targeted Structural Changes through Increase in Valence Electron Count

2009

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Section: Introductionmentioning

confidence: 99%

Gd₅Si_4−xP_x: Targeted Structural Changes through Increase in Valence Electron Count

2009

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“…A la variación de entropía magnética se añade la debida a la entropía de la red, incrementándose su efecto magnetocalórico. El primer refrigerador magnético a temperatura ambiente con imán permanente fue diseñado y construido en 2001 por la American Astronautic Corporation en colaboración con Ames Laboratory [9] (gura 1.10).…”

Section: Refrigeración Magnéticaunclassified

Estudio termo-magnético de materiales con efecto magnetocalórico gigante

Martínez¹

2008

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“…The first magnetic cooling device was developed by Brown [5] for cooling a heat load of 1.6 W using a 3 T magnetic field and He gas as the heat exchanger [117]. In 1997, the Ames laboratory and Astronautics Corporation of America developed a reciprocating magnetic cooling device using 3 kg of Gd spheres attaining a cooling power of 600 W in 5 T magnetic field [118].…”

Section: Cooling Devices Based On Mcementioning

confidence: 99%

MnNiSi based magnetocaloric alloys for cooling and energy harvesting applications

Kamble¹

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Magnetic cooling and energy harvesting technology relies on magnetocaloric materials (MCM). It has several advantages over conventional cooling technology using vapour compression systems. The aim of current research on MCMs are to develop rare-earth free, high performance, low cost, environmentally friendly and readily available materials. Since the last two decades, various MCMs addressing to specific applications have been developed and some of these applications have also been commercialized in recent years. However, most of these materials suffer from various disadvantages such as high cost, low magnetocaloric properties, poor mechanical strength, corrosion, strategic limitations and tedious synthesis routes. Hence, there has been constant endeavors to develop MCMs exhibiting wide tunability of Curie temperature (TC), good performance using low cost raw materials and simple synthesis steps. Such materials are very favorable for cooling and energy harvesting applications. Among the MCMs investigated till date, it is observed that Mn based alloys have the property to exhibit giant magnetocaloric properties. Systematic tuning of the Mn-Mn interatomic spacing can be employed to induce ferromagnetic interactions. MnNiSi alloy was selected as the base material for the present work considering the cost of raw materials. This alloy exhibits both structural transformation and magnetic transition at 1200 K and 600 K, respectively. Substitutional alloying of MnNiSi can decrease the TC and induce a coupling of magnetic and structural transition. Single element substitution by Fe can reduce the TC upto 438 K. To further bring down the TC to near room temperature, double element substitution, e.g., by Fe and Ge, is required. (MnNiSi)1-x(Fe2Ge)x alloys, synthesized by arc melting, exhibited a magnetostructural transition at temperatures ranging from 363 K to 218 K by varying x from 0.32 to 0.36, respectively. The heating and cooling cycles displayed a thermal hysteresis of ~15 K. The steep magnetic transition along with structural transformation resulted in a giant magnetocaloric response with ΔSmax = 57.6 Jkg-1 K-1 , for a ΔH of 5 T at 301 K for x = 0.34. The alloy with x = 0.35 displayed an RCP of 480 Jkg-1. The phase transition was modeled Abstract xiv using Arrott plots, Landau theory and the Bean-Rodbell model to study the first order transition and identify the phase transition parameters. Low cost, Ge-free MnNiSi based alloys, (Mn0.45Fe0.55)Ni(Si1-ySny) were synthesized by arc melting. The TC varied from 352 K to 255 K by varying the Sn content from y = 0.12 to y = 0.18. Magnetostructural coupling was observed for y = 0.12 to 0.16. A decrease in magnetostructural coupling during the first three heating and cooling cycles were observed due to Sn atoms hindering the martensitic phase transition. The magnetocaloric measurements showed reasonable values of ΔSmax = 8.6 Jkg-1 K-1 for a field change of 5 T at 315 K for y = 0.14 and the highest RCP of 252 Jkg-1 was displayed by y = 0.18. Cost analysis of the raw materials r...

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Design of Active Magnetic Regenerative Stage Interfacing to a G-M Cryocooler

Cited by 4 publications

References 2 publications

Gd₅Si_4−xP_x: Targeted Structural Changes through Increase in Valence Electron Count

Gd₅Si_4−xP_x: Targeted Structural Changes through Increase in Valence Electron Count

Estudio termo-magnético de materiales con efecto magnetocalórico gigante

MnNiSi based magnetocaloric alloys for cooling and energy harvesting applications

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Design of Active Magnetic Regenerative Stage Interfacing to a G-M Cryocooler

Cited by 4 publications

References 2 publications

Gd5Si4−xPx: Targeted Structural Changes through Increase in Valence Electron Count

Gd5Si4−xPx: Targeted Structural Changes through Increase in Valence Electron Count

Estudio termo-magnético de materiales con efecto magnetocalórico gigante

MnNiSi based magnetocaloric alloys for cooling and energy harvesting applications

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Product

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Gd₅Si_4−xP_x: Targeted Structural Changes through Increase in Valence Electron Count

Gd₅Si_4−xP_x: Targeted Structural Changes through Increase in Valence Electron Count