Destabilization and diffusion of two-dimensional close-packed Pt clusters on Pt(111) during film growth from the vapor phase

被引:7
作者
Munger, EP [1 ]
Chirita, V [1 ]
Sundgren, JE [1 ]
Greene, JE [1 ]
机构
[1] Linkoping Univ, Dept Phys, Div Thin Film, S-58183 Linkoping, Sweden
关键词
destabilization; diffusion; Pt clusters;
D O I
10.1016/S0040-6090(97)01138-3
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
Cluster migration is known to be an important process during film growth at elevated temperatures, but relatively little quantitative data is available. We have used molecular dynamics simulations to follow the dynamics of small two-dimensional Pt clusters on Pt(lll) at 1000 K. While close-packed Pt-7 heptamers are extremely stable structures, the addition of a single-cluster vacancy or an on-top adatom immediately results in intracluster bond breaking, reconfigurations, rotations, the introduction of stacking faults, and greatly enhanced cluster-diffusion rates. Mapping center-of-mass motion for total simulation times > 145 ns revealed increases in cluster velocities by more than an order of magnitude with cluster migration occurring primarily by concerted motion and a novel diffusion mechanism involving double shearing of dimers/trimers. Contrary to some previous reports, edge-atom diffusion plays only a minor role. (C) 1998 Elsevier Science S.A.
引用
收藏
页码:57 / 60
页数:4
相关论文
共 25 条
[1]   THE HOMOEPITAXIAL GROWTH OF PT ON PT(111) STUDIED WITH STM [J].
BOTT, M ;
MICHELY, T ;
COMSA, G .
SURFACE SCIENCE, 1992, 272 (1-3) :161-166
[2]   New approach for determination of diffusion parameters of adatoms [J].
Bott, M ;
Hohage, M ;
Morgenstern, M ;
Michely, T ;
Comsa, G .
PHYSICAL REVIEW LETTERS, 1996, 76 (08) :1304-1307
[3]   ENERGETICS OF SMALL PT CLUSTERS ON PT(111) - EMBEDDED-ATOM-METHOD CALCULATIONS AND PHENOMENOLOGY [J].
FALLIS, MC ;
DAW, MS ;
FONG, CY .
PHYSICAL REVIEW B, 1995, 51 (12) :7817-7826
[4]   ENERGETICS OF PT ADSORPTION ON PT(111) [J].
FEIBELMAN, PJ ;
NELSON, JS ;
KELLOGG, GL .
PHYSICAL REVIEW B, 1994, 49 (15) :10548-10556
[5]  
Greene J. E., 1993, HANDB CRYST GROWTH, V1, P639
[6]   NUCLEATION AND INITIAL GROWTH OF IN DEPOSITED ON SI3N4 USING LOW-ENERGY (LESS-THAN-OR-EQUAL-TO-300 EV) ACCELERATED BEAMS IN ULTRAHIGH-VACUUM [J].
HASAN, MA ;
BARNETT, SA ;
SUNDGREN, JE ;
GREENE, JE .
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS, 1987, 5 (04) :1883-1887
[7]   Atomic processes in low temperature Pt-dendrite growth on Pt(III) [J].
Hohage, M ;
Bott, M ;
Morgenstern, M ;
Zhang, ZY ;
Michely, T ;
Comsa, G .
PHYSICAL REVIEW LETTERS, 1996, 76 (13) :2366-2369
[8]   ANALYTIC NEAREST-NEIGHBOR MODEL FOR FCC METALS [J].
JOHNSON, RA .
PHYSICAL REVIEW B, 1988, 37 (08) :3924-3931
[9]   FIELD-ION MICROSCOPE STUDIES OF SINGLE-ATOM SURFACE-DIFFUSION AND CLUSTER NUCLEATION ON METAL-SURFACES [J].
KELLOGG, GL .
SURFACE SCIENCE REPORTS, 1994, 21 (1-2) :1-88
[10]   SURFACE-DIFFUSION MODES FOR PT DIMERS AND TRIMERS ON PT(001) [J].
KELLOGG, GL ;
VOTER, AF .
PHYSICAL REVIEW LETTERS, 1991, 67 (05) :622-625