Gd_(99.75)Fe_(0.25)合金的大磁热效应及应用特性研究  

Large Magnetocaloric Effect and Application Features of Gd_(99.75)Fe_(0.25) Alloy

作　　者：闵继雄[1] 钟喜春[1] 郑志刚[1] 刘仲武[1] 曾德长[1] 余红雅[1] 邱万奇[1] 

机构地区：[1]华南理工大学,广东广州510640

出　　处：《稀有金属材料与工程》2013年第2期362-365,共4页Rare Metal Materials and Engineering

基　　金：广东省科技计划项目(2010B050300008,2007B010600043);广东省教育部产学研结合项目(2010A090200042,2009B090300273);国家自然科学基金(U0734001,50874050);中央高校基本科研业务费专项资金项目(2009ZM0291,2009ZZ0025,2009ZM0247)

摘　　要：采用X射线衍射、物理性能测试系统、显微硬度计及电化学工作站研究了经氩弧熔炼、1123K均匀化热处理168h的Gd99.75Fe0.25合金的磁热效应及应用特性。结果表明:Gd99.75Fe0.25合金仍保持纯Gd的六方晶体结构;Gd99.75Fe0.25合金的居里温度为294K,且在居里点附近发生铁磁到顺磁的二级相变,2和5T外场下的最大磁熵变分别为4.99和9.37J·kg-1·K-1,均大于纯Gd;Gd99.75Fe0.25合金的显微硬度(HV0.2)590MPa,与纯Gd相当,但少量Fe的掺杂提高了Gd的耐蚀性。含少量Fe的Gd99.75Fe0.25合金具有大的磁热效应及良好的应用特性,是一种有很大应用潜力的室温磁致冷材料。Gd99.75Fe0.25 alloy prepared by arc melting under purified argon atmosphere and homogenization annealing treatment at 1123 K for 168 h was investigated by X-ray diffraction, physical property measurement system, microhardness tester and electrochemical workstation. The results show that the Gd99.75Fe0.25 alloy still retains hexagonal crystal structure of pure Gd. The Curie temperature of Gd99.75Fe0.25 alloy is 294 K, and the alloy exhibits a second-order magnetic transition from ferromagnetism to paramagnetism. The maximum magnetic entropy changes of Gd99.75Fe0.25 alloy under magnetic field changes of 0-2 T and 0-5 T are 4.99 J·k^g-1·K^-1 and 9.37 J·kg-1·K-1, respectively, which are larger than that of pure Gd. The micro-hardness （HV0.2） of Gd99.75Fe0.25 alloy is 590 MPa, which is equivalent to that of pure Gd. But the corrosion resistance is improved by doping a small amount of Fe. Large magnetocaloric effect and good application features make the Gd99.75Fe0.25 alloy as a potential magnetic refrigerant at room temperature.

关 键 词：磁热效应 Gd99 75Fe0 25 合金 磁熵变 应用特性 

分 类 号：TG166[金属学及工艺—热处理]