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Magnetic refrigeration—towards room-temperature applications
- Source :
-
Physica B . Apr2003, Vol. 327 Issue 2-4, p431. 7p. - Publication Year :
- 2003
-
Abstract
- Modern society relies very much on readily available cooling. Magnetic refrigeration based on the magneto-caloric effect (MCE) has become a promising competitive technology for the conventional gas-compression/expansion technique in use today. Recently, there have been two breakthroughs in magnetic-refrigeration research: one is that American scientists demonstrated the world''s first room-temperature, permanent-magnet, magnetic refrigerator; the other one is that we discovered a new class of magnetic refrigerant materials for room-temperature applications. The new materials are manganese–iron–phosphorus–arsenic (MnFe(P,As)) compounds. This new material has important advantages over existing magnetic coolants: it exhibits a huge MCE, which is larger than that of Gd metal; and its operating temperature can be tuned from about 150 to about 335 K by adjusting the P/As ratio. Here we report on further improvement of the materials by increasing the Mn content. The large entropy change is attributed to a field-induced first-order phase transition enhancing the effect of the applied magnetic field. Addition of Mn reduces the thermal hysteresis, which is intrinsic to the first-order transition. This implies that already moderate applied magnetic fields of below 2 T may suffice. [Copyright &y& Elsevier]
- Subjects :
- *MAGNETISM
*MAGNETIC fields
Subjects
Details
- Language :
- English
- ISSN :
- 09214526
- Volume :
- 327
- Issue :
- 2-4
- Database :
- Academic Search Index
- Journal :
- Physica B
- Publication Type :
- Academic Journal
- Accession number :
- 9281724
- Full Text :
- https://doi.org/10.1016/S0921-4526(02)01769-6