Characterization of a new Nb-silicide (-Nb11Si4) in Nb-Si binary systems

被引：15

作者：

Cheng, Guangming ^{[1
]}

Qian, Haiyan ^{[2
]}

He, Lianlong ^{[1
]}

Ye, Hengqiang ^{[1
,3
]}

机构：

[1] Chinese Acad Sci, Shenyang Natl Lab Mat Sci, Inst Met Res, Shenyang 110016, Peoples R China

[2] Shanghai Univ, Inst Mat Sci, Shanghai 200072, Peoples R China

[3] Peking Univ, Electron Microscope Lab, Beijing 100871, Peoples R China

来源：

PHILOSOPHICAL MAGAZINE | 2010年 / 90卷 / 19期

基金：

中国国家自然科学基金;

关键词：

microstructure; precipitation; niobium-silicide; orientation relationship; transmission electron microscopy; ORIENTATION RELATIONSHIP; PHASE-STABILITY; COMPOSITES; ALLOYS;

D O I：

10.1080/14786431003630827

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

A new Nb-silicide, -Nb11Si4, identified as a second phase precipitated from a Nb-Si solid solution, was characterized by combining crystallographic analysis with first-principles calculations. The crystal structure was determined as a body-centered orthorhombic system with space group Immm using transmission electron microscope (TEM). Based on the crystallographic relationship between the and Nb phases, [image omitted] // {200}Nb and [image omitted] // < 001 > Nb, eight possible unit cells were proposed, which were optimized by first-principles calculations. By analyzing the experimental and calculated data, we obtained the final unit cell of the phase, which was confirmed by high-resolution TEM images. In addition, density of states and electron density difference of -Nb11Si4 revealed that the structure was in a metastable state at low temperature because not all the bonding states were filled.

引用

页码：2557 / 2568

页数：12

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