Superhard nitride-based nanocomposites: Role of interfaces and effect of impurities

被引：116

作者：

Hao, Shiqiang ^{[1
]}

Delley, Bernard

Veprek, Stan

Stampfl, Catherine

机构：

[1] Univ Sydney, Sch Phys, Sydney, NSW 2006, Australia

[2] WHGA, Paul Scherrer Inst, CH-5232 Villigen, Switzerland

[3] Tech Univ Munich, Dept Chem, D-85747 Garching, Germany

来源：

PHYSICAL REVIEW LETTERS | 2006年 / 97卷 / 08期

关键词：

D O I：

10.1103/PhysRevLett.97.086102

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

Recently, a hardness similar to that of diamond has been reported for a quasiternary, nitride-based nanocomposite. The related, quasibinary nanocomposite "nc-TiN/a-Si3N4," which may be regarded as the prototype of the family of superhard nc-metal-N/a-Si3N4 systems, also exhibits a significant hardness enhancement. Extensive density-functional theory calculations indicate that the superhardness is related to the preferential formation of TiN(111) polar interfaces with a thin beta-Si3N4-derived layer. The strength of TiN in the < 111 > direction is similar to that of the weakest bonding direction in diamond. Oxygen impurities cause a significant reduction of the interface strength.

引用

页数：4

共 27 条

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