Adiabatic temperature change of micro- and nanocrystalline Y2Fe17 heat-exchangers for magnetic cooling

Abstract Magnetic refrigerants are used as heat exchangers to provide rapid heat transfer between magnetocaloric materials and heat-transfer liquid. An important question is how to turn bulk magnetocaloric materials into porous structures with superior heat transfer properties and cooling performance. We discuss two methods for assembling Y 2 Fe 17 rapidly quenched ribbons into heat exchangers of desired geometry - stacked 100 μm thick plates with 100 μm gaps: the first method consists in gluing rapidly quenched ribbons using thermoconductive epoxy; the second is sintering stacked ribbons at a temperature of 30 K below the melting point of the Y 2 Fe 17 phase. These approaches are promising with regards to making near-net shaped magnetic refrigerants. We report on adiabatic temperature change ΔT ad , magnetic entropy change ΔS m and thermal conductivity λ of rapidly quenched Y 2 Fe 17 ribbons, obtained at different quenching rates. A direct correlation between the lattice parameters of the Y 2 Fe 17 , ΔT ad and ΔS m in rapidly quenched samples is observed.