Effects of surface vibrations on interlayer mass transport: Ab initio molecular dynamics investigation of Ti adatom descent pathways and rates from TiN/TiN(001) islands

作     者：D. G. Sangiovanni A. B. Mei D. Edström L. Hultman V. Chirita I. Petrov J. E. Greene 

作者机构：Atomistic Modelling and Simulation Interdisciplinary Centre for Advanced Materials Simulation (ICAMS) Ruhr-Universität Bochum D-44801 Bochum Germany Thin Film Physics Division Department of Physics Chemistry and Biology (IFM) Linköping University SE-58183 Linköping Sweden Departments of Materials Science Physics and the Frederick Seitz Materials Research Laboratory University of Illinois Urbana Illinois 61801 USA Department of Materials Science and Engineering Cornell University Ithaca New York 14853 USA 

出 版 物：《Physical Review B》 (Phys. Rev. B)

年 卷 期：2018年第97卷第3期

页      面：035406-035406页

核心收录：

基　　金：VINNOVA Knut och Alice Wallenbergs Stiftelse, (2011.0094) Knut och Alice Wallenbergs Stiftelse Stiftelsen Olle Engkvist Byggmästare, (2016/408) Stiftelsen Olle Engkvist Byggmästare Vetenskapsrådet, VR, (2008-6572, 2013-4018, 2014-5790) Vetenskapsrådet, VR 

主　　题：Adsorption Crystal growth Island Lattice dynamics Surface diffusion Ceramics Nitrides Transition metals Density functional calculations Molecular dynamics 

摘      要：We carried out density-functional ab initio molecular dynamics (AIMD) simulations of Ti adatom (Tiad) migration on, and descent from, square TiN〈100〉 epitaxial islands on TiN(001) at temperatures (T) ranging from 1200 to 2400 K. Adatom-descent energy barriers determined via ab initio nudged-elastic-band calculations at 0 Kelvin suggest that Ti interlayer transport on TiN(001) occurs essentially exclusively via direct hopping onto a lower layer. However, AIMD simulations reveal comparable rates for Tiad descent via direct hopping vs push-out/exchange with a Ti island-edge atom for T≥1500K. We demonstrate that this effect is due to surface vibrations, which yield considerably lower activation energies at finite temperatures by significantly modifying the adatom push-out/exchange reaction pathway.