Atomic-Resolution Imaging of the Nanoscale Origin of Toughness in Rare-Earth Doped SiC

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• 作者：Aaron M. Kueck ; Do Kyung Kim ; Quentin M. Ramasse ; L. C. De Jonghe ; R. O. Ritchie
• 刊名：Nano Letters
• 出版年：2008
• 出版时间：September 10, 2008
• 年：2008
• 卷：8
• 期：9
• 页码：2935-2939
• 全文大小：312K
• 年卷期：v.8,no.9(September 10, 2008)
• ISSN：1530-6992

文摘

Ultrahigh-resolution transmission electron microscopy and atomic-scale spectroscopy are used to investigate the origin of the toughness in rare-earth doped silicon carbide (RE-SiC) by examining the mechanistic nature of the intergranular cracking events which we find to occur precisely along the RE-decorated interface between the SiC grains and the nanoscale grain-boundary phase. We conclude that, for optimal toughness, the relative elastic modulus across the grain-boundary phase and the interfacial fracture toughness are the most critical material parameters; both can be altered with judicious choice of rare-earth elements.