First-Principles Study of Formation and Properties of Fcc-NdOx in Nd-Fe-B Sintered Magnets
First-Principles Study of Formation and Properties of Fcc-NdOx in Nd-Fe-B Sintered Magnets
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DOI：
10.4028/www.scientific.net/msf.654-656.1674
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发表时间：
2010-06
期刊：
影响因子：
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通讯作者：
Ying Chen;S. Hirosawa;S. Iwata
中科院分区：
文献类型：
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作者：
Ying Chen;S. Hirosawa;S. Iwata
在Nd溅射Nd-Fe-B烧结磁体中，Nd/Nd-Fe-B界面处形成的NdOx相对Nd-Fe-B晶粒的矫顽力产生起着重要作用，近年来引起了人们的广泛关注。它的晶体结构随氧浓度的变化而变化，由Nd_2O_3-C型结构衍生的无序fcc相是其主要存在形式。为了理解这种fcc-NdOx界面相的形成机理，从第一性原理出发研究了Nd-O体系在所有氧浓度范围内的稳定性。基于LSDA+U方法对Nd-O中不同氧浓度下的有序相进行了计算，并采用团簇展开法（CEM）计算了无序相的形成能、态密度等性质。
The NdOx phase formed at the Nd/Nd-Fe-B interface in Nd-sputtered Nd-Fe-B sintered magnets is paid rather attention recently due to its important role in coercivity generation of surface Nd-Fe-B grains. Its crystal structures have been reported to vary with the change of the oxygen concentration, and the disorder fcc phase derived from Nd2O3-C-type structure to be the main form of existence. To understand the formation mechanism of this fcc-NdOx interfacial phase, the stability of all oxygen concentration range of Nd-O system has been investigated from the first principles. Based on LSDA+U calculations for selected ordered phases at various oxygen concentration in Nd-O, the Cluster Expansion Method (CEM) is applied to evaluate the formation energy, density of states and other properties of disorder phase.