Gd_(3)Al_(2-x)Ga_(x)合金的磁性与磁热效应  

Magnetism and magnetocaloric effect of Gd_(3)Al_(2-x)Ga_(x)alloys

作　　者：生利英[1] 宋博宇[1] 冯岩青 刘翠兰[2] 高磊 SHENG Liying;SONG Boyu;FENG Yanqing;LIU Cuilan;GAO Lei(Material Engineering Department,Baotou Vocational and Technical College,Baotou 014030,Nei Mongol,China;Baotou Research Institute of Rare Earth,Baotou 014010,Nei Mongol,China)

机构地区：[1]包头职业技术学院材料系,内蒙古包头014030 [2]包头稀土研究院,内蒙古包头014010

出　　处：《金属功能材料》2024年第6期219-226,共8页Metallic Functional Materials

基　　金：稀土磁制冷材料Gd3(AlGa)2系合金结构和磁性的研究(HJZY23024);大制冷温区磁制冷材料性能与制冷能力优化研究(52066001)。

摘　　要：磁制冷技术具有绿色环保、高能效、运行可靠等优点,成为制冷领域研究的焦点。采用真空电弧熔炼技术,制备了Gd_(3)Al_(2-x)Ga_(x)(x=0.0、0.1、0.2、0.3)合金,系统地分析了合金的微观结构、磁性和磁热效应。研究结果表明,Gd_(3)Al_(2)合金由Gd_(3)Al_(2)相、GdAl相、Gd_(2)Al相构成。随着Ga含量的增加,杂相GdAl相和Gd_(2)Al相含量逐渐减少,主相Gd_(3)Al_(2)相含量逐渐增加。在Gd_(3)Al_(2)合金中,Ga元素的引入可以起到调控微观结构的作用。M-T曲线表明,Gd_(3)Al_(2)、Gd_(3)Al_(1.9)Ga_(0.1)、Gd_(3)Al_(1.8)Ga_(0.2)和Gd_(3)Al_(1.7)Ga_(0.3)合金的居里温度分别为274、276、274、276K,表明Gd_(3)Al_(2-x)Ga_(x)合金可在室温附近应用。M-H曲线说明,Gd_(3)Al_(2-x)Ga_(x)合金在居里温度附近经历顺磁到铁磁转变,为二级磁相变材料。在0~3T下,Gd_(3)Al_(2-x)Ga_(x)(x=0.0、0.1、0.2、0.3)合金的最大等温磁熵变分别为3.04、3.23、3.26、3.57J·kg^(-1)·K^(-1),RCP分别为157.54、184.67、184.39、200.42J·kg^(-1)。0~2T下,Gd_(3)Al_(2-x)Ga_(x)(x=0.0、0.1、0.2、0.3)合金的最大绝热温变分别为2.76、3.02、3.37、3.59K。合适的居里温度、优异的磁热效应表明,Gd_(3)Al_(2-x)Ga_(x)(x=0.0、0.1、0.2、0.3)合金可作为一种候选室温磁制冷材料。Magnetic refrigeration technology has the advantages of green environment,high energy efficiency and reliable operation,which has become the focus of research in the field of refrigeration.The Gd_(3)Al_(2-x)Ga_(x)(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 Gd_(3)Al_(2)alloy consists of Gd_(3)Al_(2)phase,GdAl phase,and Gd_(2)Al phase.With the increase of Ga content,the content of heterogeneous phases GdAl phase and Gd_(2)Al phase gradually decreases,and the content of main phase Gd_(3)Al_(2)phase gradually increases.For Gd_(3)Al_(2)-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 Gd_(3)Al_(2)、Gd_(3)Al_(1.9)Ga_(0.1)、Gd_(3)Al_(1.8)Ga_(0.2)and Gd_(3)Al_(1.7)Ga_(0.3)alloys are 274,276,274,and 276K,respectively,which indicate that Gd_(3)Al_(2-x)Ga_(x)alloys can be applied near room temperature.The M-Hcurves illustrate that every Gd_(3)Al_(2-x)Ga_(x)alloy undergoes a paramagnetic to ferromagnetic transition near the Curie temperature and belongs to the second order magnetic transition material.The maximum isothermal magnetic entropy changes of Gd_(3)Al_(2-x)Ga_(x)(x=0.0,0.1,0.2,0.3)alloys are 3.04,3.23,3.26,3.57J·kg^(-1)·K^(-1),with RCPs of 157.54,184.67,184.39,and 200.42J·kg^(-1),respectively,at 0-3T.The maximum adiabatic temperature changes of Gd_(3)Al_(2-x)Ga_(x)(x=0.0,0.1,0.2,0.3)alloys are 2.76,3.02,3.37,3.59K,respectively.Suitable Curie temperature and excellent MCE suggest that Gd_(3)Al_(2-x)Ga_(x)(x=0.0,0.1,0.2,0.3)alloys can be a candidate for room-temperature magnetic refrigerants.

关 键 词：磁制冷 Gd_(3)Al_(2-x)Ga_(x)合金 微观结构 磁热效应 

分 类 号：TG1[金属学及工艺—金属学]