New Magnetic Refrigeration Materials for the Liquefaction of Hydrogen

Gschneidner, K. A.; Takeya, Hiroyuki; Moorman, J. O.; Pecharsky, V. K.; Malik, S. K.; Zimm, C. B.

doi:10.1007/978-1-4615-2522-6_179

Cited by 37 publications

(27 citation statements)

References 10 publications

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“…As the authors have shown, this is one case where determining the MCE properties by another technique (magnetization) proved to be critical and helped to avoid reporting erroneous data. Gschneidner et al (36,96) suggested that (Dy 0.5 Er 0.5 )Al 2 might be a useful alloy as an active magnetic regenerator material in a magnetic refrigerator for liquefying hydrogen gas. Földeaki et al (77) noted that the MCE ( S M ) was increased by ∼10% by grinding a (Dy 0.5 Er 0.5 )Al 2 alloy relative to the as cast material.…”

Section: Aluminidesmentioning

confidence: 99%

“…A series of pseudo-binary (Dy 1−x Er x ) Al 2 alloys were studied by Gschneidner and co-workers (24,26,36,37,96) using magnetic susceptibility, dc magnetization and heat capacity measurements, whereas Földeaki et al (77) studied the (Dy 0.5 Er 0.5 )Al 2 composition. The Curie temperatures decrease linearly with increasing x from 63.9 for DyAl 2 to 13.6 K for ErAl 2 , except for x = 0.25, which shows a slight dip from the straight line established by the other compositions (37).…”

Section: Aluminidesmentioning

confidence: 99%

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Magnetocaloric Materials

Gschneidner

Pecharsky

2000

Annu. Rev. Mater. Sci.

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1,266

568

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Key Words magnetocaloric effect, mixed lanthanide materials, 3d-materials amorphous alloys, manganites s Abstract In the last decade of the twentieth century there has been a significant increase in research on a more than 100-year old phenomenon-the magnetocaloric effect (MCE). As a result, many new materials with large MCEs (and many with lesser values) have been discovered, and a much better understanding of this magneto-thermal property has resulted. In this review we briefly discuss the principles of magnetic cooling (and heating); the measurement of the magnetocaloric properties by direct and indirect techniques; the special problems that can arise; and the MCE properties of the 4f lanthanide metals, their intra-lanthanide alloys and their compounds [including the giant MCE Gd 5 (Si x Ge 1−x ) 4 phases]; the 3d transition metals, their alloys and compounds; and mixed lanthanide-3d transition metal materials (including the La manganites). INTRODUCTIONCommercial and residential refrigeration is a mature, relatively low capital cost but a high-energy demand industry. Even the newest most efficient units operate well below the maximum theoretical (Carnot) efficiency, and few, if any, further improvements may be possible with the existing vapor-cycle technology. Magnetic refrigeration (MR), however, is rapidly becoming competitive with conventional gas compression technology because it offers considerable operating cost savings by eliminating the most inefficient part of the refrigerator-the compressor. In addition to its energy savings potential, MR is an environmentally sound alternative to vapor-cycle refrigerators and air conditioners. Most modern refrigeration systems and air conditioners still use ozone-depleting or global-warming volatile liquid refrigerants. Magnetic refrigerators use a solid refrigerant(s) and common heat transfer fluids (e.g. water, water-alcohol solution, air, or helium gas) with no ozone-depleting and/or global-warming effects.Magnetic refrigeration is based on the magnetocaloric effect (MCE). The MCE, or adiabatic temperature change ( T ad ), which is detected as the heating or the cooling of magnetic materials due to a varying magnetic field, was originally discovered in iron by Warburg (1). The thermodynamics of the MCE was understood 0084-6600/00/0801-0387$14.00 387 Annu. Rev. Mater. Sci. 2000.30:387-429. Downloaded from www.annualreviews.org by Fordham University on 11/22/12. For personal use only. 388GSCHNEIDNER PECHARSKY by Debye (2) and by Giauque (3), both of whom independently suggested that it could be used to reach low temperatures in a process known as adiabatic demagnetization. Soon after this discovery, an operating adiabatic demagnetization refrigerator was constructed and utilized by Giauque & McDougal (4) to reach 0.53, 0.34, and 0.25 K starting at 3.4, 2.0, and 1.5 K, respectively, using a magnetic field of 0.8 T and 61 g of Gd 2 (SO 4 ) 3 ·8H 2 O as the magnetic refrigerant. The MCE is intrinsic to any magnetic material. In the case of a ferromagnet near its mag...

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Section: Aluminidesmentioning

confidence: 99%

Section: Aluminidesmentioning

confidence: 99%

Magnetocaloric Materials

Gschneidner

Pecharsky

2000

Annu. Rev. Mater. Sci.

Self Cite

1,266

568

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“…The magnetocaloric effect is being exploited not only for room-temperature refrigeration but also for a variety of other cooling applications ranging from production of low temperatures (millikelvin) to room-temperature refrigeration [3,4]. The phenomenon of the magnetocaloric effect can also be perceived as a heat engine and hence assumes significance for heating applications, too [5].…”

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confidence: 99%

Inverse magnetocaloric effect in sol–gel derived nanosized cobalt ferrite

et al. 2010

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The magnetocaloric properties of cobalt ferrite nanoparticles were investigated to evaluate the potential of these materials as magnetic refrigerants. Nanosized cobalt ferrites were synthesized by the method of sol-gel combustion. The nanoparticles were found to be spherical with an average crystallite size of 14 nm. The magnetic entropy change ( S m ) calculated indirectly from magnetization isotherms in the temperature region 170-320 K was found to be negative, signifying an inverse magnetocaloric effect in the nanoparticles. The magnitudes of the S m values were found to be larger when compared to the reported values in the literature for the corresponding ferrite materials in the nanoregime.

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“…Generally, due to their large magnetic moments, heavy rare earth elements and their compounds are considered the best-suited materials for achieving large MCE. After the observation 1 of a giant MCE in Gd 5 Si 2 Ge 2 and the studies on the pseudo-binary systems 8 like R 5 (Si x Ge 1-x ) 4 with R= La, Lu, Nd and Dy, much interest has been focused on the compounds showing field-induced magnetic phase transitions and/or structural transitions. But the magnetocaloric studies in MnFeP 1-x As x system 9 has shown that large MCE is not just restricted to the compounds with large magnetic moments but depends strongly on the type of magnetic/structural phase transitions as well.…”

mentioning

confidence: 99%