Magnetic cooling by an adiabatic spin reorientation
A new method of magnetic cooling is proposed by using an adiabatic entropy change associated with a spin reorientation transition. This is available for a magnetic refrigerator operating under a weaker magnetic field than an ordinary method using a superconducting magnet to cool a paramagnetic crystal. The single crystal and sintered samples of ErCrO/sub 3/ were adopted as a prototype material. The sample was set in the adiabatic cell and put in a sweeping magnetic field. The cooling was observed in the range from 2 to 11 K. A maximum cooling of 0.4 degrees was obtained for the single crystal just below the transition temperature TSR (= 9.8 K) in a magnetic field of 200 Oe after applying the correction of the demagnetizing effect. The entropy vs temperature diagram of ErCrO/sub 3/ was determined from measurements of the specific heat. The complete analogy between thermodynamic properties of the spin reorientation transition with those of a liquid-gas system suggests a possibility of an application to a heat engine. Such a device might be useful for maintaining a temperature lower than the transition temperature by a permanent magnet.
- Research Organization:
- Broadcasting Science Research Laboratories of NHK, Setagaya-ku, Tokyo
- OSTI ID:
- 5226320
- Journal Information:
- IEEE Trans. Magn.; (United States), Journal Name: IEEE Trans. Magn.; (United States) Vol. MAG-20:5; ISSN IEMGA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360603 -- Materials-- Properties
420201* -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ADIABATIC DEMAGNETIZATION
CHALCOGENIDES
CHROMIUM COMPOUNDS
CHROMIUM OXIDES
CONTROL
CRYSTALS
ELECTRICAL EQUIPMENT
ELECTROMAGNETS
ENGINES
ENTROPY
EQUIPMENT
ERBIUM COMPOUNDS
ERBIUM OXIDES
FLUIDS
GASES
HEAT ENGINES
LIQUIDS
MAGNETIC FIELDS
MAGNETIC REFRIGERATORS
MAGNETISM
MAGNETS
MATERIALS
MATERIALS TESTING
MONOCRYSTALS
ORIENTATION
OXIDES
OXYGEN COMPOUNDS
PARAMAGNETISM
PERMANENT MAGNETS
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
REFRIGERATORS
SINTERED MATERIALS
SPECIFIC HEAT
SPIN ORIENTATION
SUPERCONDUCTING DEVICES
SUPERCONDUCTING MAGNETS
TEMPERATURE CONTROL
TESTING
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE