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Hier finden Sie wissenschaftliche Publikationen aus den FraunhoferInstituten. The basic structure of TiSiN superhard nanocomposite coatings: Ab initio studies
 Nagel, W.E. ; Höchstleistungsrechenzentrum, Stuttgart: High performace computing in science and engineering. Transactions of the High Performance Computing Center Stuttgart (HLRS) 2007 : Tenth Results and Review Workshop on High Performance Computing in Science and Engineering, which was held October 4  5, 2007 at Stuttgart University Berlin: Springer, 2008 ISBN: 9783540747383 ISBN: 3540747389 ISBN: 9783540747390 S.117136 
 Workshop on High Performance Computing in Science and Engineering (HLRS) <10, 2007, Stuttgart> 

 Englisch 
 Konferenzbeitrag 
 Fraunhofer IPA () 
 coating; Ab initio Methode; Nanomaterial; Titan; Titannitrid; Silicium; Nitrid; Beschichten 
Abstract
A new interface structure, the cross double tetrahedron Si4N4Ti, is reported in this paper. To find out the atomic structure of TiSiN superhard nanocomposite coatings, total energy calculations for the different configurations of TiN with Si addition were performed with the ab initio method. The calculation results indicate that (a) there is no interstitial solid solution of Si in the TiN crystallite under the equilibrium condition; (b) the basic structure of the TiSiN composite is the TiN crystallite with the cross double tetrahedron Si4N4Ti in the boundary of TiN. The cross double tetrahedron Si4N4Ti is an intrinsic mismatch to the B1NaCl structure of TiN and it fills the boundary with the covalent combination. The TiN boundary is strengthened and the inter diffusion through the boundary is restricted by the interface Si4N4Ti so that the hardness and the thermal stability of TiSiN coatings are enhanced. As a fixation element to the rock salt structure, the potential value of the cross double tetrahedron is in the mass production of nanometer patterns or the quantum dots. The formation of the Si4N4Ti in the film growth process is also studied. The study indicates that Si4N4Ti cannot be formed in the island of TiN on the TiN (001) surface. Under some pressure conditions, Si will stay outside the island of TiN. The investigation of the Si distribution in TiN demonstrated that the congregation of the Si4N4Ti structures in TiN will result in an increase in the local strain and a decrease in the cohesive energy of the system.