Mn含量对Mn_(2-x)Sn_(0.5)Ga_(0.5) Heusler合金磁及磁热性能的影响  

Effect of Mn Concentration on the Magnetic and Magnetocaloric Properties for Mn_(2-x)Sn_(0.5)Ga_(0.5) Heusler alloys

作　　者：缪小吉 孙斐[1] 胡静 Miao Xiaoji;Sun Fei;Hu Jing(Institute of Modern Equipment Manufacturing,Changzhou Institute of Industry Technology,Changzhou 213164,China;National Experimental Demonstration Center for Materials Science and Engineering,Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering,Changzhou University,Changzhou 213164,China)

机构地区：[1]常州工业职业技术学院现代装备制造学院,江苏常州213164 [2]常州大学材料科学与工程国家级实验教学示范中心江苏省光伏科学与工程协同创新中心,江苏常州213164

出　　处：《稀有金属材料与工程》2021年第4期1405-1408,共4页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(21978025);江苏省第三期优势学科建设项目(PAPD);江苏高校品牌专业建设工程资助项目(TAPP)。

摘　　要：选用Mn基Heusler合金为研究对象,通过电弧熔炼和热处理制备样品,并用甩带法制成薄带形状。采用X射线衍射仪和振动样品磁强计等分析仪器测试样品的晶体结构、磁及磁热性能,分析Mn含量对材料晶体结构、磁和磁热性能的影响。结果表明,Mn_(2-x)Sn_(0.5)Ga_(0.5)合金在室温下为六方结构,在室温附近仅发生一次二阶磁性转变,无明显磁滞和热滞。居里温度和饱和磁化强度对Mn含量非常敏感,随着Mn含量升高,居里温度和饱和磁化强度均出现下降,由Mn_(1.2)Sn_(0.5)Ga_(0.5)的304 K和64.1 A·m^(2)·kg^(-1)分别降至Mn_(2)Sn_(0.5)Ga_(0.5)的262 K和46.7 A·m^(2)·kg^(-1),这表明合金中的磁矩呈亚铁磁形态分布。由于没有磁滞和热滞,室温附近具有较大的工作温度区间,所以该材料在磁制冷领域具有很好的应用前景。Mn-based Heusler alloys were selected as testing materials in this research, and the samples were prepared by arc-melting, subsequent heat treatment, and made in ribbon form by melt-spinning. The effects of Mn concentration on the crystal structures, magnetic and magnetocaloric properties were studied. It was found that Mn_(2-x)Sn_(0.5)Ga_(0.5) crystallizes in hexagonal structure at the room temperature. All samples undergo only second order phase transition at their Curie temperature near room temperature with nearly zero hysteresis. The Curie temperature and the saturation magnetization of the Mn_(2-x)Sn_(0.5)Ga_(0.5) are very sensitive to Mn concentration where both Curie temperature and saturation magnetization decrease with the increase of Mn concentration, from 304 K and 64.1 A·m^(2)·kg^(-1) to 262 K and 46.7 A·m^(2)·kg^(-1) for Mn_(1.2)Sn_(0.5)Ga_(0.5)and Mn_(2)Sn_(0.5)Ga_(0.5), respectively, which indicates the ferrimagnetic order in these materials. Mn-based Heusler alloys will have a large application prospect in the field of magnetic refrigeration because of the absence of hysteresis and thermal hysteresis and with wide operating temperature range near room temperature.

关 键 词：HEUSLER合金 磁热效应 磁性能 晶体结构 

分 类 号：TB34[一般工业技术—材料科学与工程]