Magnetism and magnetocaloric effect of Gd3Al2-xGax alloys
Magnetic refrigeration technology has the advantages of green environment,high energy efficiency and re-liable operation,which has become the focus of research in the field of refrigeration.The Gd3Al2-xGax(x=0.0,0.1,0.2,0.3)alloys were prepared by vacuum arc melting technology,and the microstructure,magnetism and magnetocaloric effect(MCE)were systematically analyzed.The results show that the Gd3Al2 alloy consists of Gd3Al2 phase,GdAl phase,and Gd2Al phase.With the increase of Ga content,the content of heterogeneous phases GdAl phase and Gd2Al phase gradually decreases,and the content of main phase Gd3Al2 phase gradually increases.For Gd3Al2-series alloys,the introduction of Ga element can play a role in modulating the microstructure.The M-T curves show that the Curie temperatures of Gd3Al2、Gd3Al1.9Ga0.1、Gd3Al1.8Ga0.2 and Gd3Al1.7Ga0.3 alloys are 274,276,274,and 276 K,respectively,which indicate that Gd3Al2-xGax alloys can be applied near room temperature.The M-H curves illustrate that every Gd3Al2-xGax alloy undergoes a paramagnetic to ferromagnetic transition near the Curie temperature and belongs to the second order magnetic transition material.The maximum isothermal mag-netic entropy changes of Gd3Al2-xGax(x=0.0,0.1,0.2,0.3)alloys are 3.04,3.23,3.26,3.57 J·kg-1·K-1,with RCPs of 157.54,184.67,184.39,and 200.42 J·kg-1,respectively,at 0-3 T.The maximum adiabatic tem-perature changes of Gd3Al2-xGax(x=0.0,0.1,0.2,0.3)alloys are 2.76,3.02,3.37,3.59 K,respectively.Suit-able Curie temperature and excellent MCE suggest that Gd3Al2-xGax(x=0.0,0.1,0.2,0.3)alloys can be a candi-date for room-temperature magnetic refrigerants.
magnetic refrigerationGd3Al2-xGax alloysmicrostructuremagnetocaloric effect
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