Gd掺杂对Ni-Mn-In磁性形状记忆合金电子结构、磁性与马氏体相变影响:第一性原理计算和实验  

Impacts of Gd doping on electronic structure,magnetism,and martensitic phase transition in Ni-Mn-In magnetic shape memory alloys:first-principles calculations and experiment

作　　者：徐阳睿 辛向阳 郭欣 高丽[1] 许竞翔 XU Yangrui;XIN Xiangyang;GUO Xin;GAO Li;XU Jingxiang(College of Engineering Science and Technology,Shanghai Ocean University,Shanghai 201306,China)

机构地区：[1]上海海洋大学工程学院,上海201306

出　　处：《材料工程》2024年第9期180-189,共10页Journal of Materials Engineering

基　　金：国家自然科学基金青年科学基金(51401122)。

摘　　要：采用实验研究与第一性原理计算相结合的方法,研究了Gd掺杂对Ni-Mn-In合金的影响。第一性原理计算结果发现,在Ni_(8)Mn_(6)In_(2)中,Gd掺杂倾向于占据合金中的Ni和In的亚晶格。Gd取代Ni或In后均可提高马氏体温度,同时降低居里温度。特别是Gd取代In时,相变温度的提升更为显著。电子态密度分析表明:Gd会降低奥氏体稳定性,提高马氏体稳定性,是其相变温度升高的主要原因。采用真空电弧熔炼炉成功制备了Ni_(50-x)Mn_(35)In_(15)Gd_(x)(x=0,1,2)和Ni_(50)Mn_(35)In_(15-x)Gd_(x)(x=0,1,2)多晶合金,通过DSC实验数据分析,Gd的掺杂提升了合金的相变温度,其中Ni_(50)Mn_(35)In_(13)Gd_(2)的马氏体转变开始温度达到160℃,可以满足高温(≈97℃)的工作条件,在单个Gd原子的掺杂下未改变合金母相和马氏体相的磁状态,对磁化强度差的影响较小,阐明了Gd掺杂对合金的磁结构影响机理。The impact of Gd doping on Ni-Mn-In alloys was investigated using a combination of experimental studies and first-principles calculations.The results of first-principles calculations reveal that Gd doping tends to occupy the sublattices of Ni and In in the Ni_(8)Mn_(6)In_(2) alloy.Gd substitution of either Ni or In increases the martensitic temperature and decreases the Curie temperature at the same time.In particular,the increase in phase transition temperature is more significant after Gd replaces In.The electron density of states analysis shows that Gd doping decreases the austenite stability and increases the martensite stability,which is the main reason for the increase in phase transition temperature.The Ni_(50-x)Mn_(35)In_(15)Gd_(x)(x=0,1,2)and Ni_(50)Mn_(35)In_(15-x)Gd_(x)(x=0,1,2)polycrystalline alloys are successfully prepared using a vacuum arc melting furnace,and analyzed by the DSC experimental data,it was observed that the doping of Gd enhances the phase transition temperature of alloy.Specifically,the martensitic transformation starts temperature of Ni_(50)Mn_(35)In_(13)Gd_(2) reached 160℃,which can meet the high-temperature(≈97℃)operating conditions.The doping of a single Gd atom does not change the magnetic state of the alloy parent phases and martensitic phases in Ni-Mn-In alloys,resulting in a minor effect on the difference of magnetization.The mechanism of Gd doping affects the magnetic structure of the alloy is elucidated.

关 键 词：第一性原理 磁性形状记忆合金 马氏体相变 电子结构 

分 类 号：TG139.6[一般工业技术—材料科学与工程]