M. D. Kuz'min

Heat exchangers made of polymer-bonded La(Fe,Si)13

We report on magnetocaloric properties of polymer-bonded La(Fe,Si)13 heat exchangers with respect to the grain size of the powder used and the pressure applied for compaction of plates. Quite remarkably, it was found that the values of the adiabatic temperature change of polymer-bonded plates are 10% higher than in the initial bulk material. A critical value of the pressure applied during the compaction was found. Exceeding this value leads to a drastic reduction of the magnetocaloric effect due to cracking and comminution of the initial 50–100 μm grains down to 1–10 μm fragments. Compacting the LaFe11.6Si1.4 powder with 5 wt. % of silver epoxy under an optimal pressure of 0.1 GPa resulted in the production of 0.6 mm-thick plates. These plates were subsequently stacked and glued together into a simple porous heat exchanger with straight 0.6 mm-width channels.

Magnetic field dependence of the maximum adiabatic temperature change

The field dependence of the maximum magnetocaloric ΔT-effect in ferromagnets with second-order phase transitions is studied by way of direct measurements. All studied materials are found to follow the formula ΔTmax=A(H+H0)2/3-AH02/3, where A and H0 are constants and H is the internal magnetic field. It is essential to distinguish the latter from external field Hext. The dependence of ΔTmax on Hext is qualitatively distinct, the difference being particularly pronounced in the low-field region. In the field range relevant to applications (0.1–2 T), ΔTmax follows a linear dependence on H2/3. It is proposed to use the slope of this dependence as a figure of merit of magnetic refrigerants.

Magnetic properties of ( Fe 1 − x Co x ) 2 B alloys and the effect of doping by 5 d elements

We have explored, computationally and experimentally, the magnetic properties of \fecob{} alloys. Calculations provide a good agreement with experiment in terms of the saturation magnetization and the magnetocrystalline anisotropy energy with some difficulty in describing Co

Magnetic properties of (Fe1-xCox)(2)B alloys and the effect of doping by 5d elements

_2

Influence of thermal treatment on magnetocaloric properties of Gd cold rolled ribbons

B, for which it is found that both full potential effects and electron correlations treated within dynamical mean field theory are of importance for a correct description. The material exhibits a uniaxial magnetic anisotropy for a range of cobalt concentrations between

Magnetic Properties of (Fe,Co) 2 B Alloys With Easy-Axis Anisotropy

x=0.1

Magnetization of a Dy2Fe14Si3single crystal in high magnetic fields

and

Magnetic properties of(Fe1−xCox)2Balloys and the effect of doping by5delements

x=0.5

Magnetic field dependence of the maximum magnetic entropy change

. A simple model for the temperature dependence of magnetic anisotropy suggests that the complicated non-monotonous temperature behaviour is mainly due to variations in the band structure as the exchange splitting is reduced by temperature. Using density functional theory based calculations we have explored the effect of substitutional doping the transition metal sublattice by the whole range of 5

Spin reorientation in high magnetic fields and the Co-Gd exchange field in GdCo5

d