Optimization of the refrigerant capacity in multiphase magnetocaloric materials

Abstract

The effect of distributed exchange parameters on magnetocaloric refrigeration capacity in amorphous and nanocomposite materials J. Appl. Phys. 111, 07A334 (2012); 10.1063/1.3679456Large magnetocaloric effect and refrigerant capacity in Gd-Co-Ni metallic glasses

Influence of magnetic interactions between phases on the magnetocaloric effect of composites

“…It has been recently shown theoretically that composite materials constituted by different phases with a second order phase transition can exhibit greatly enhanced refrigerant capacities (RC), and table-like magnetocaloric effect. 13 This has been subsequently confirmed by experimental results by different groups, [14][15][16] finding an outstanding agreement between experimental results and predictions of the models. 16 However, these studies of materials with different magnetic phases do not consider the possible effect of the interactions among the phases, which might alter the response of the materials.…”

“…In fact, there are experimental observations which indicate that this coexistence of phases affect dynamic properties such as the magnetic resonance spectra. 13 However, first order phase transition magnetocaloric materials are not the only kind of systems in which different magnetic phases coexist. It has been recently shown theoretically that composite materials constituted by different phases with a second order phase transition can exhibit greatly enhanced refrigerant capacities (RC), and table-like magnetocaloric effect.…”

Enhanced refrigerant capacity and magnetic entropy flattening using a two-amorphous FeZrB(Cu) composite

“…However, sintered mixtures of compounds are not well suited because they behave as a material with a single T C [5]. Instead of that, the design of specific composites [6][7][8] can lead to an enlargement of the MCE temperature span and an almost constant ΔS M (T) curve. The efficiency of the magnetic material in terms of the energy transfer between the cold (T cold ) and hot (T hot ) reservoirs, is quantified by its refrigerant capacity, RC, an important figure of merit that characterizes the magnetocaloric material [9,10]:…”

“…show that the design and practical realization of multiphase or composite magneto-3 caloric materials with optimized RC and ΔS M (T) curves is not a simple task [4][5][6]. For a two-phase composite the magnetic field variation of the RC is complex, and depends on several factors such as ΔT C and the shape, width and peak value of ΔS M (T) curve of the two constituents [6].…”

“…For a two-phase composite the magnetic field variation of the RC is complex, and depends on several factors such as ΔT C and the shape, width and peak value of ΔS M (T) curve of the two constituents [6].…”