Ab-Initio Simulation Laboratory

Citation:

Chang, C. M., Wei C. M., & Chen S. P. (1996).  Modeling of Ir adatoms on Ir surfaces. Physical Review B. 54, 17083-17096., Dec, Number 23

Abstract:

We used the embedded-atom method potential to study the structures, adsorption energies, binding energies, migration paths, and energy barriers of the Ir adatom and small clusters on fcc Ir (100), (110), and (111) surfaces. We found that the barrier for single-adatom diffusion is lowest on the (111) surface, higher on the (110) surface, and highest on the (100) surface. The exchange mechanisms of adatom diffusion on (100) and (110) surfaces are energetically favored. On all three Ir surfaces, Ir-2 dimers with nearest-neighbor spacing are the most stable. On the (110) surface, the Ir-2 dimer diffuses collectively along the (110) channel, while motion perpendicular to the channel walls is achieved by successive one-atom and correlated jumps. On (111) surface, the Ir-2 dimer diffuses in a zigzag motion on hcp and fee sites without breaking into two single atoms. On the (100) surface, diffusion of the Ir-2 dimer is achieved by successive one-atom exchange with the substrate atom accompanying by a 90 degrees rotation of the Ir-2 dimer. This mechanism has a surprisingly low activation energy of 0.65 eV, which is 0.14 eV lower than the energy for single adatom exchange on the (100) surface. Trimers were found to have a one-dimensional (1D) structure on (100) and (110) surfaces, and a 2D structure on the (111) surface. The observed abrupt drop of the diffusion barrier of tetramer, I-gamma 4 on the Ir (111) surface was confirmed theoretically.

Notes:

ISI Document Delivery No.: WA833Times Cited: 29Cited Reference Count: 69Cited References: ADAMS JB, 1989, J MATER RES, V4, P102, DOI 10.1557/JMR.1989.0102 AYRAULT G, 1974, J CHEM PHYS, V60, P281, DOI 10.1063/1.1680781 BASSETT DW, 1978, SURF SCI, V70, P520, DOI 10.1016/0039-6028(78)90429-6 Bassett D.W., 1969, British Journal of Applied Physics (Journal of Physics D), V2 BASSETT DW, 1976, J PHYS C SOLID STATE, V9, P2491, DOI 10.1088/0022-3719/9/13/009 CAMPBELL GH, 1993, PHYS REV LETT, V70, P449, DOI 10.1103/PhysRevLett.70.449 CHEN C, 1991, PHYS REV LETT, V66, P1610, DOI 10.1103/PhysRevLett.66.1610 CHEN CL, 1990, PHYS REV B, V41, P12403, DOI 10.1103/PhysRevB.41.12403 CHEN CL, 1990, PHYS REV LETT, V64, P3147, DOI 10.1103/PhysRevLett.64.3147 CHEN CL, 1990, APPL PHYS A-MATER, V51, P405, DOI 10.1007/BF00348381 CHEN SP, 1991, SURF SCI, V244, pL107, DOI 10.1016/0039-6028(91)90162-L CHEN SP, 1989, J MATER RES, V4, P62, DOI 10.1557/JMR.1989.0062 CHEN SP, 1986, PHYS REV LETT, V57, P1308, DOI 10.1103/PhysRevLett.57.1308 CHEN SP, 1990, J MATER RES, V5, P955, DOI 10.1557/JMR.1990.0955 CHEN SP, 1992, PHILOS MAG A, V66, P1 CHEN SP, 1992, SURF SCI, V274, pL619, DOI 10.1016/0039-6028(92)90835-T CHEN SP, 1992, SURF SCI, V264, pL162, DOI 10.1016/0039-6028(92)90148-Y COWAN P, 1975, PHYS LETT A, V53, P383, DOI 10.1016/0375-9601(75)90040-7 DAW MS, 1985, SOLID STATE COMMUN, V56, P697, DOI 10.1016/0038-1098(85)90781-1 DAW MS, 1983, PHYS REV LETT, V50, P1285, DOI 10.1103/PhysRevLett.50.1285 DAW MS, 1984, PHYS REV B, V29, P6443, DOI 10.1103/PhysRevB.29.6443 DHANAK VR, 1990, SURF SCI, V238, P289, DOI 10.1016/0039-6028(90)90087-O DOLL JD, 1982, J CHEM PHYS, V77, P479, DOI 10.1063/1.443630 EHRLICH G, 1991, SURF SCI, V246, P1, DOI 10.1016/0039-6028(91)90385-6 EHRLICH G, 1966, J CHEM PHYS, V44, P1039, DOI 10.1063/1.1726787 EHRLICH G, 1994, SURF SCI, V299, P628, DOI 10.1016/0039-6028(94)90685-8 EINSTEIN TL, 1990, SURF SCI, V227, P114, DOI 10.1016/0039-6028(90)90398-R EINSTEIN TL, 1991, LANGMUIR, V7, P2520, DOI 10.1021/la00059a021 EINSTEIN TL, 1995, PHYSICAL STRUCTURE S, pCH11 FEIBELMAN PJ, 1994, PHYS REV B, V49, P10548, DOI 10.1103/PhysRevB.49.10548 FEIBELMAN PJ, 1990, PHYS REV LETT, V65, P729, DOI 10.1103/PhysRevLett.65.729 FLYNN CP, 1972, POINT DEFECTS DIFFUS, pCH7 FOILES SM, 1985, PHYS REV B, V32, P3409, DOI 10.1103/PhysRevB.32.3409 FOILES SM, 1986, PHYS REV B, V33, P7983, DOI 10.1103/PhysRevB.33.7983 GRAHAM WR, 1974, SURF SCI, V45, P530, DOI 10.1016/0039-6028(74)90187-3 GRAVIL PA, 1994, SURF SCI, V310, P267, DOI 10.1016/0039-6028(94)91390-0 HAMILTON JC, 1995, PHYS REV LETT, V74, P2760, DOI 10.1103/PhysRevLett.74.2760 KARIMI M, 1992, PHYS REV B, V45, P6289, DOI 10.1103/PhysRevB.45.6289 KELLOGG GL, 1990, PHYS REV LETT, V64, P3143, DOI 10.1103/PhysRevLett.64.3143 LIU CL, 1991, SURF SCI, V253, P334, DOI 10.1016/0039-6028(91)90604-Q LIU CL, 1992, SURF SCI, V265, P262, DOI 10.1016/0039-6028(92)90506-2 LYNDENBELL RM, 1991, SURF SCI, V259, P129, DOI 10.1016/0039-6028(91)90531-V MCDOWELL HK, 1983, J CHEM PHYS, V78, P3219, DOI 10.1063/1.445238 Muller E. W., 1969, FIELD ION MICROSCOPY NELSON JS, 1989, PHYS REV B, V40, P1465, DOI 10.1103/PhysRevB.40.1465 NELSON JS, 1988, PHYS REV LETT, V61, P1977, DOI 10.1103/PhysRevLett.61.1977 NELSON RC, 1993, SURF SCI, V295, P462, DOI 10.1016/0039-6028(93)90293-S PARK SC, 1984, J CHEM PHYS, V80, P2191, DOI 10.1063/1.446907 RILLING WK, 1990, CAN J PHYS, V68, P1035 ROELOFS LD, 1991, STRUCTURE SURFACES, V3, P248 ROSE JH, 1984, PHYS REV B, V29, P2963, DOI 10.1103/PhysRevB.29.2963 SCHWOEBEL PR, 1988, PHYS REV B, V38, P5326, DOI 10.1103/PhysRevB.38.5326 TIAN ZJ, 1993, PHYS REV B, V47, P9751, DOI 10.1103/PhysRevB.47.9751 TSONG TT, 1991, PHYS REV B, V43, P2007, DOI 10.1103/PhysRevB.43.2007 TSONG TT, 1991, SURF SCI, V246, P13, DOI 10.1016/0039-6028(91)90386-7 TSONG TT, 1992, CCAST WL SW, V9, P75 TSONG TT, 1975, THIN SOLID FILMS, V25, P97, DOI 10.1016/0040-6090(75)90250-3 TULLY JC, 1979, J CHEM PHYS, V71, P1630, DOI 10.1063/1.438490 TUNG R, 1980, THESIS U PENNSYLVANI TUNG RT, 1980, SURF SCI, V97, P73, DOI 10.1016/0039-6028(80)90104-1 Voter AF, 1987, MATER RES SOC S P, V82, P175 WANG SC, 1990, SURF SCI, V239, P301, DOI 10.1016/0039-6028(90)90232-W WANG SC, 1991, SURF SCI, V246, P37, DOI 10.1016/0039-6028(91)90389-A WILSON WD, 1981, PHYS REV B, V24, P5616, DOI 10.1103/PhysRevB.24.5616 WRIGLEY JD, 1980, PHYS REV LETT, V44, P661, DOI 10.1103/PhysRevLett.44.661 XU W, 1994, SURF SCI, V301, P371, DOI 10.1016/0039-6028(94)91317-X XU W, 1994, SURF SCI, V319, P45, DOI 10.1016/0039-6028(94)90568-1 YANG LQ, 1991, PHYS REV B, V44, P13725, DOI 10.1103/PhysRevB.44.13725 ZANGWILL A, 1988, PHYSICS SURFACESChang, CM Wei, CM Chen, SPAMER PHYSICAL SOCCOLLEGE PK

Website