Magnetic and Thermal Properties of Dy3Al5O12 as a Magnetic Refrigerant
We investigated the magnetic entropy of Dy3AlsO12 (DAG), which is one of the most promising refrigerants for the Carnot-type magnetic refrigerator. In the present investigation we measured the specific heat in zero magnetic field and the magnetization as a function of temperature and magnetic field, and from the analysis of these experimental results, the magnetic entropy change ΔSJ and entropy S are obtained. The values of ΔSJ and S of DAG were compared with those of Gd3Ga5O12(GGG), which is frequently used as a refrigerant for the Carnot-type magnetic refrigerator. The g-factor of the magnetic ion in DAG was shown to play a more important role in determining ΔSJ near 20 K than the J-value. It is therefore clear that DAG is a more useful refrigerant than GGG for the Carnot-type refrigerator having a broad temperature span from ~20 K to 4.2 K.
KeywordsMagnetic Field Magnetic Field Strength Total Entropy Magnetocaloric Effect Magnetic Entropy Change
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