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Simulation calculations of surface segregation for Au–Cu alloys using an analytic embedded atom model
Author(s) -
Bangwei Zhang,
Taglauer Edmund,
Xiaolin Shu,
Wangyu Hu,
Huiqiu Deng
Publication year - 2005
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.200520092
Subject(s) - alloy , atom (system on chip) , materials science , monte carlo method , layer (electronics) , metal , thermodynamics , copper , surface energy , crystallography , chemistry , metallurgy , physics , nanotechnology , statistics , mathematics , computer science , embedded system
The key problem for applying the Monte Carlo (MC) method to segregation lies in the selection of an appropriate energy model for the simulations. Zhang et al. proposed a modified analytic embedded atomic method (MAEAM), which has been applied to a variety of fundamental problems in metals and alloys. We used this MAEAM and MC method for the simulations of segregation of AuCu and Au 3 Cu alloys. For the (100) surface, the calculations show that Au is enriched in the 1 st layer (70 at% for AuCu, 99 at% for Au 3 Cu), while Cu is enriched in the 2 nd layer (50–62 at% for AuCu, 35–48 at% for Au 3 Cu). The composition profiles are generally oscillating. For the (111) surface, we also found Au to be enriched in the 1 st layer. However, Cu is not enriched in the 2 nd layer, it reaches the bulk composition from 2 nd to 4 th layer. Au increases from 92 to 97 at% and 99 to 100 at% for Au 3 Cu(111) and (100), respectively, when the temperature varies from 1000 to 200 K, which is basically in agreement with the measurements for Au 3 Cu(100) by Taglauer et al. However, the Au concentration does not change for the AuCu alloy in the same temperature range. We also calculate the segregation energy, the simulation results agree qualitatively with the experimental data available. Our results demonstrate that the MAEAM model provides an effective means for simulating the segregation of alloys. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)