Quantitative LEED I-V and ab initio study of the Si(111)-3x2-Sm surface structure and the missing half-order spots in the 3x1 diffraction pattern

C. Eames; M. I. J. Probert; S. P. Tear

doi:10.1103/PhysRevB.75.205420

Quantitative LEED I-V and ab initio study of the Si(111)-3x2-Sm surface structure and the missing half-order spots in the 3x1 diffraction pattern

C. Eames, M. I. J. Probert, S. P. Tear

Physics

Research output: Contribution to journal › Article › peer-review

Abstract

We have used low-energy electron diffraction (LEED) I-V analysis and ab initio calculations to quantitatively determine the honeycomb chain model structure for the Si(111)-3x2-Sm surface. This structure and a similar 3x1 recontruction have been observed for many alkali-earth and rare-earth metals on the Si(111) surface. Our ab initio calculations show that there are two almost degenerate sites for the Sm atom in the unit cell, and the LEED I-V analysis reveals that an admixture of the two in a ratio that slightly favors the site with the lower energy is the best match to experiment. We show that the I-V curves are insensitive to the presence of the Sm atom and that this results in a very low intensity for the half-order spots, which might explain the appearance of a 3x1 LEED pattern produced by all of the structures with a 3x2 unit cell.

Original language	English
Article number	205420
Pages (from-to)	-
Number of pages	9
Journal	Physical Review B
Volume	75
Issue number	20
DOIs	https://doi.org/10.1103/PhysRevB.75.205420
Publication status	Published - May 2007

Keywords

ENERGY-ELECTRON DIFFRACTION
RECONSTRUCTIONS
NA
YB

Access to Document

10.1103/PhysRevB.75.205420

http://dx.doi.org/10.1103/PhysRevB.75.205420

Cite this

@article{4e5a8add287542d98a2c22ea9bf055ee,

title = "Quantitative LEED I-V and ab initio study of the Si(111)-3x2-Sm surface structure and the missing half-order spots in the 3x1 diffraction pattern",

abstract = "We have used low-energy electron diffraction (LEED) I-V analysis and ab initio calculations to quantitatively determine the honeycomb chain model structure for the Si(111)-3x2-Sm surface. This structure and a similar 3x1 recontruction have been observed for many alkali-earth and rare-earth metals on the Si(111) surface. Our ab initio calculations show that there are two almost degenerate sites for the Sm atom in the unit cell, and the LEED I-V analysis reveals that an admixture of the two in a ratio that slightly favors the site with the lower energy is the best match to experiment. We show that the I-V curves are insensitive to the presence of the Sm atom and that this results in a very low intensity for the half-order spots, which might explain the appearance of a 3x1 LEED pattern produced by all of the structures with a 3x2 unit cell.",

keywords = "ENERGY-ELECTRON DIFFRACTION, RECONSTRUCTIONS, NA, YB",

author = "C. Eames and Probert, {M. I. J.} and Tear, {S. P.}",

year = "2007",

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doi = "10.1103/PhysRevB.75.205420",

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journal = "Physical Review B",

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TY - JOUR

T1 - Quantitative LEED I-V and ab initio study of the Si(111)-3x2-Sm surface structure and the missing half-order spots in the 3x1 diffraction pattern

AU - Eames, C.

AU - Probert, M. I. J.

AU - Tear, S. P.

PY - 2007/5

Y1 - 2007/5

N2 - We have used low-energy electron diffraction (LEED) I-V analysis and ab initio calculations to quantitatively determine the honeycomb chain model structure for the Si(111)-3x2-Sm surface. This structure and a similar 3x1 recontruction have been observed for many alkali-earth and rare-earth metals on the Si(111) surface. Our ab initio calculations show that there are two almost degenerate sites for the Sm atom in the unit cell, and the LEED I-V analysis reveals that an admixture of the two in a ratio that slightly favors the site with the lower energy is the best match to experiment. We show that the I-V curves are insensitive to the presence of the Sm atom and that this results in a very low intensity for the half-order spots, which might explain the appearance of a 3x1 LEED pattern produced by all of the structures with a 3x2 unit cell.

AB - We have used low-energy electron diffraction (LEED) I-V analysis and ab initio calculations to quantitatively determine the honeycomb chain model structure for the Si(111)-3x2-Sm surface. This structure and a similar 3x1 recontruction have been observed for many alkali-earth and rare-earth metals on the Si(111) surface. Our ab initio calculations show that there are two almost degenerate sites for the Sm atom in the unit cell, and the LEED I-V analysis reveals that an admixture of the two in a ratio that slightly favors the site with the lower energy is the best match to experiment. We show that the I-V curves are insensitive to the presence of the Sm atom and that this results in a very low intensity for the half-order spots, which might explain the appearance of a 3x1 LEED pattern produced by all of the structures with a 3x2 unit cell.

KW - ENERGY-ELECTRON DIFFRACTION

KW - RECONSTRUCTIONS

KW - NA

KW - YB

U2 - 10.1103/PhysRevB.75.205420

DO - 10.1103/PhysRevB.75.205420

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SN - 1098-0121

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JO - Physical Review B

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