2018新材料国际发展趋势高层论坛

胡凤霞

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职位/职称: 研究员

单位: 中国科学院物理研究所

报告论坛: 先进磁性材料分论坛

报告题目: Solid refrigeration materials

简历:

胡凤霞,中国科学院物理研究所研究员。主要学术成绩包括:发现了新型 La(Fe,Si)13基大磁热效应材料,室温磁熵变值超过传统稀土材料Gd的2倍。获2014年度陈嘉庚技术科学奖(2)、2012年度国家自然科学二等奖(2)、2011年度北京市科学技术奖一等奖(2)。

摘要:

Solid refrigeration technology based on magnetocaloric, barocaloric/elastocaloric, and eletrocaloric effect has attracted world-wide attention due to the numerous advantages over vapor compression refrigeration which have low efficiencies and negative environmental effects. The coupling of magnetic and structural transition, i.e. magnetostructural transition, is usually sensitive to magnetic field and stress, thereby leading to giant magnetocaloric effect (MCE) and barocaloric/elastocaloric effect.
Here we report stress modulated phase transition and multi-field driven magnetocaloric effect for the well-known La(Fe,Co,Si)13 [1], Ni2In-type MM'X materials, and RGa/RCo2 compounds. For a room temperature La(Fe,Co,Si)13 magnetocaloric material, enhanced magnetocaloric effect (MCE) by hydrostatic pressure has been demonstrated by magnetic measurements under pressure. To understand the origin, we performed neutron powder diffraction (NPD) studies on the crystal and magnetic structures as a function of temperature under different pressures [2]. The change of atomic local environments and 5 kinds of Fe-Fe bonds (B1-B5) with pressure were illustrated. The result indicates that hydrostatic pressure is an effective way to dig the lattice contribution. Moreover, from the viewpoint of application, magnetocaloric properties of thin plates were studied for La(Fe,Si)13-based materials. Strengthened mechanical properties and enhanced age stability have been achieved in the hydrogenated La(Fe,Si)13H plates as thin as 0.40.6mm with extra Fe or introducing Cu/Pb metal as binders, meanwhile the MCE remains large [3]. MnCoGe-based alloys with magnetostructural transition show giant negative thermal expansion behavior [4] and MCE, but the bad mechanical properties obstruct their practical applications. We successfully grew Mn-Co-Ge-In films on different substrate, which completely overcome the breakable nature and tunable MCE around room temperature has been observed owing to the stress from substrate [5]. Moreover, we also studied stress modulated spin orientation and magnetic transition in a number of heavy rare earth (R)-based compounds [6], enhanced MCE has been demonstrated in some of them

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重要日期

会议开始时间

2018-09-16

会议结束时间

2018-09-18

报到时间

2018-09-16

poster提交截止日期

2018-08-30

报告人摘要提交截止日期

2018-08-25

联系方式

王方 
电话:029-86226599
传真:029-86282362
materialschina@163.com


王媛
电话: 13464049904
yuan209108@imr.ac.cn 

富甘霖(参展及赞助)
电话:13811320379 
13811320379@163.com

高虹(财务)
电话:029-86226599
传真:029-86282362
zgcljz@126.com

 

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