Room temperature active regenerative magnetic refrigeration: Magnetic nanocomposites

Abstract

Nanocomposites have several advantages as a refrigerant for 100–300 K applications compared to the other common methods of assembling a magnetic refrigeration bed, such as a layered thermal bed, or mixing of different magnetic materials. This article discusses the thermodynamics and heat transfer analysis of an ideal and real active magnetic regenerative refrigeration cycle. An algorithm for the choice of optimum parameters is derived.

Optimization of the refrigerant capacity in multiphase magnetocaloric materials

“…Single-phase materials exhibiting large RC values are rare, and there is considerable research toward expanding ␦T through various methods, including amorphization by ball milling, 5 modifying the structure by microalloying 6 and annealing, 7,8 nanostructuring, 9 developing composites 10,11 and nanocomposites, [12][13][14] and employing multilayered materials. 15,16 All of these methods involve either the existence of a Curie temperature distribution in the magnetic material, or the presence of several phases that contribute to the total ⌬S M .…”

Magnetic entropy change in bulk nanocrystalline Gd metals

“…Considerable investigations indicate that the nanostructured materials are very promising candidates for potential application in the magnetic refrigeration (Zhang et al 2001;Tanaka et al 2001;Hueso et al 2002;Provenzanoa et al 2003;Shir et al 2003;Kinoshita et al 2004;Evangelisti et al 2005;Poddar et al 2006;Gómez-Polo et al 2007;Ma et al 2007;Baldomir et al 2007;Franco et al 2007;škorvánek et al 2007;Poddar et al 2007;Biswas et al 2008;Franco et al 2008;Gorsse et al 2008;Li 2008;Gass et al 2008;Lu et al 2008;Santanna et al 2008;Serantes et al 2008;Pekała and Drozd 2008;Juan and Gui 2009;Gorria et al 2009;Phan et al 2009;Babita et al 2009;Calderon-Ortiz et al 2009;Das et al 2009;Phan et al 2010;Burianova et al 2010;Nelson et al 2002). However, up to now, not much effort has been devoted to the rare earth bulk nanocrystalline metals.…”

A constant magnetocaloric response in FeMoCuB amorphous alloys with different Fe∕B ratios

“…Moreover, composites with a constant entropy change between the hot and cold reservoirs have been considered among the optimum materials for active magnetic regenerative refrigerators. 21,22 Hence, materials with a constant value of ͉⌬S M pk ͉ and different Curie temperatures could be a good starting point for the development of such composites. One of the objectives of this work is to show that the B substitution for Fe in nanoperm type alloys with low B content permits one to adjust the temperature at which MCE has a maximum response, keeping constant the peak entropy change of the alloys.…”