Magnetocaloric effect in some magnetic materials in alternating magnetic fields up to 22 Hz

JOURNAL OF ALLOYS AND COMPOUNDS

卷:676

Article

Aliev, A. M.¹  Batdalov, A. B.¹  Khanov, L. N.¹  Koledov, V. V.²  Shavrov, V. G.²  Tereshina, I. S.³  Taskaev, S. V.⁴ 

[1] RAS, Daghestan Sci Ctr, Amirkhanov Inst Phys, Makhachkala, Russia

[2] RAS, Kotelnikov Inst Radio Engn & Elect, Moscow 117901, Russia

[3] RAS, Baikov Inst Met & Mat Sci, Moscow 117901, Russia

[4] Chelyabinsk State Univ, Chelyabinsk, Russia

关键词: Magnetocaloric effect;    Alternating magnetic field;    Frequency;    Gadolinium;    Heusler alloy;   

DOI  :  10.1016/j.jallcom.2016.03.238

来源: Elsevier

【 摘 要 】

Direct measurements of the magnetocaloric effect (MCE) in different materials (Gd, Fe48Rh52, Ni43Mn37.9In12.1Co7 and Ni2.07Co0.09Mn0.84Ga) in alternating magnetic fields with frequencies f <= 22 Hz and an amplitude Delta H = 6.2 kOe are carried out. The MCE in Gd shows inconsiderable changes with field frequency. Near paramagnetic-ferromagnetic phase transition in Ni43Mn37.9In12.1Co7 Heusler alloy a slight reduction of MCE with frequency is observed. In weak alternating fields in materials with AFM-FM magneto-structural phase transitions (Fe48Rh52, Ni43Mn37.9In12.1Co7) it is not possible to get a structural contribution to overall MCE because of irreversibility of the transitions in these fields. Near magneto-structural phase transitions the MCE in these alloys has only magnetic contribution, and does not show a significant dependence on the magnetic field frequency. In Ni2.07Co0.09Mn0.84Ga Heusler alloy the MCE vanishes at frequencies about 20 Hz. The obtained results show the increase of frequencies of operating cycles is one of the powerful methods to improve the efficiency of magnetic refrigerators in case of Gd as a refrigerant.

【 授权许可】

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