skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Phase and Amplitude Recover and Diffraction Image Generation Method: Structure of Sb/Au(110)-3 x 3R54.7 degrees from Surface X-ray Diffraction

Abstract

The discovery that the phase problem of diffraction from non-periodic objects may be solved by oversampling the diffraction intensities in reciprocal space with respect to a Nyquist criterion has opened up new vistas for structure determination by diffraction methods. A similar principle may be applied to the problem of surface X-ray diffraction (SXRD), where, owing to the breaking of a crystal periodicity normal to its surface, diffraction data consist of a set of superstructure rods (SRs) due to scattering from the parts of the surface whose structure is different from that of the truncated bulk and of crystal truncation rods (CTRs), formed by interfering contributions from the surface and the bulk. A phase and amplitude recovery and diffraction image generation method (PARADIGM) is described that provides a prescription for finding the unmeasured amplitudes and phases of the surface contributions to the CTRs in addition to the phases of the SRs, directly from the diffraction data. The resulting 'diffraction image' is the basis of a determination of the previously unknown multidomain structure of Sb/Au(110)-{radical}3 x 3R54.7{sup o}.

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
930458
Report Number(s):
BNL-81210-2008-JA
Journal ID: ISSN 0108-7673; TRN: US200904%%729
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: Acta Crystallographica Section A: Foundations of Crystallography; Journal Volume: 63
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; AMPLITUDES; CRYSTAL STRUCTURE; DIFFRACTION; DIFFRACTION METHODS; PERIODICITY; SCATTERING; X-RAY DIFFRACTION; national synchrotron light source

Citation Formats

Fung,R., Shneerson, V., Lyman, P., Parihar, S., Johnson-Steigelman, H., and Saldin, D.. Phase and Amplitude Recover and Diffraction Image Generation Method: Structure of Sb/Au(110)-3 x 3R54.7 degrees from Surface X-ray Diffraction. United States: N. p., 2007. Web. doi:10.1107/S0108767307002930.
Fung,R., Shneerson, V., Lyman, P., Parihar, S., Johnson-Steigelman, H., & Saldin, D.. Phase and Amplitude Recover and Diffraction Image Generation Method: Structure of Sb/Au(110)-3 x 3R54.7 degrees from Surface X-ray Diffraction. United States. doi:10.1107/S0108767307002930.
Fung,R., Shneerson, V., Lyman, P., Parihar, S., Johnson-Steigelman, H., and Saldin, D.. Mon . "Phase and Amplitude Recover and Diffraction Image Generation Method: Structure of Sb/Au(110)-3 x 3R54.7 degrees from Surface X-ray Diffraction". United States. doi:10.1107/S0108767307002930.
@article{osti_930458,
title = {Phase and Amplitude Recover and Diffraction Image Generation Method: Structure of Sb/Au(110)-3 x 3R54.7 degrees from Surface X-ray Diffraction},
author = {Fung,R. and Shneerson, V. and Lyman, P. and Parihar, S. and Johnson-Steigelman, H. and Saldin, D.},
abstractNote = {The discovery that the phase problem of diffraction from non-periodic objects may be solved by oversampling the diffraction intensities in reciprocal space with respect to a Nyquist criterion has opened up new vistas for structure determination by diffraction methods. A similar principle may be applied to the problem of surface X-ray diffraction (SXRD), where, owing to the breaking of a crystal periodicity normal to its surface, diffraction data consist of a set of superstructure rods (SRs) due to scattering from the parts of the surface whose structure is different from that of the truncated bulk and of crystal truncation rods (CTRs), formed by interfering contributions from the surface and the bulk. A phase and amplitude recovery and diffraction image generation method (PARADIGM) is described that provides a prescription for finding the unmeasured amplitudes and phases of the surface contributions to the CTRs in addition to the phases of the SRs, directly from the diffraction data. The resulting 'diffraction image' is the basis of a determination of the previously unknown multidomain structure of Sb/Au(110)-{radical}3 x 3R54.7{sup o}.},
doi = {10.1107/S0108767307002930},
journal = {Acta Crystallographica Section A: Foundations of Crystallography},
number = ,
volume = 63,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • Adsorption of 0.5 monolayers (ML) of Sb on the Au(1 1 0) surface resulted in the formation of a c(2 x 2) surface reconstruction. Analysis of surface X-ray diffraction data by a direct method revealed the existence of an ordered substitutional surface alloy, with every other hollow site occupied by Au and Sb atoms. Quantitative conventional {chi}{sup 2} refinement showed a contraction of 0.12 {+-} 0.03 Angstroms in the spacing of the first Au layer to the second, an expansion of 0.13 {+-} 0.03 Angstroms in the second-to-third layer distance, and an inward Sb displacement (rumpling) of 0.21 {+-} 0.04more » Angstroms. This surface phase proved to be extremely robust, with the long-range order of this arrangement remaining up to substrate temperatures of 900 K.« less
  • Sb [ital L]-edge absorption fine structure has been measured to study the bonding geometry of the (1 monolayer Sb)/GaP(110) interface. The polarization dependence of these measurements confirms that the Sb zigzag chains lie nearly parallel to the GaP surface. The Sb-P, Sb-Ga, and Sb-Sb bond lengths are determined to be 2.60[plus minus]0.05, 2.79[plus minus]0.05, and 2.88[plus minus]0.05 A, respectively. These values are better characterized by sums of covalent radii than by bond lengths determined in total-energy-minimization calculations.
  • The structures of two ferroic chloroantimonates(III): [(CH{sub 3}){sub 2}NH{sub 2}]{sub 3}[Sb{sub 2}Cl{sub 9}] (DMACA) and [(CH{sub 3}){sub 3}NH]{sub 3}[Sb{sub 2}Cl{sub 9}] (TMACA) were determined in their low-temperature phases. The structure of DMACA was investigated at 100 and 15K, and TMACA at 15K. The structures consist of two-dimensional inorganic layers and organic cations bound together by the N(C)-H...Cl hydrogen bonds. All of the organic cations in both compounds at all studied temperatures are ordered. There is no indication of the structural phase transition in the structure of DMACA below 242K. The geometry and distortions of the [SbCl{sub 6}]{sup 3-} octahedra inmore » both compounds is discussed. The monoclinic Pc space group was found for both compounds: DMACA a=9.3590(5), b=9.0097(4), c=14.1308(7)A, {beta}=95.229(4){sup o}, R{sub 1}=0.0240, wR{sub 2}=0.0491 and a=9.3132(4), b=9.0008(3), c=14.1088(5)A, {beta}=95.010(3){sup o}, R{sub 1}=0.0230, wR{sub 2}=0.0482 at 100 and 15K, respectively; TMACA a=9.8652(5), b=9.1129(4), c=15.0964(7)A, {beta}=89.988(4){sup o}, R{sub 1}=0.0239, wR{sub 2}=0.0611 at 15K.« less
  • [ital In] [ital situ] x-ray scattering studies of the Au(110) electrode surface have been carried out in 0.1[ital M] NaF, NaCl, NaBr, LiCl, CsCl, and HClO[sub 4] solutions under potential control. At sufficiently negative potentials, in the salt solutions the surface forms a (1[times]3) reconstruction rather than a (1[times]2) reported for the clean vacuum surface. Above a critical threshold potential, the (1[times]3) reconstruction vanishes and the surface forms a (1[times]1) structure.
  • The structure of Bi{sub 2}Te{sub 3} (Seebeck coefficient Standard Reference Material (SRM™ 3451)) and the related phase Sb{sub 2}Te{sub 3} have been characterized as a function of temperature using the neutron powder diffraction (NPD) and the extended X-ray absorption fine structure (EXAFS) techniques. The neutron structural studies were carried out from 20 K to 300 K for Bi{sub 2}Te{sub 3} and from 10 K to 298 K for Sb{sub 2}Te{sub 3}. The EXAFS technique for studying the local structure of the two compounds was conducted from 19 K to 298 K. Bi{sub 2}Te{sub 3} and Sb{sub 2}Te{sub 3} are isostructural, with a space group of R3{supmore » ¯}m. The structure consists of repeated quintuple layers of atoms, Te2-M-Te1-M-Te2 (where M = Bi or Sb) stacking along the c-axis of the unit cell. EXAFS was used to examine the bond distances and static and thermal disorders for the first three shells of Bi{sub 2}Te{sub 3} and Sb{sub 2}Te{sub 3} as a function of temperature. The temperature dependencies of thermal disorders were analyzed using the Debye and Einstein models for lattice vibrations. The Debye and Einstein temperatures for the first two shells of Bi{sub 2}Te{sub 3} are similar to those of Sb{sub 2}Te{sub 3} within the uncertainty in the data. However, the Debye and Einstein temperatures for the third shell of Bi-Bi are significantly lower than those of the third shell of Sb-Sb. The Einstein temperature for the third shell is consistent with a soft phonon mode in both Bi{sub 2}Te{sub 3} and Sb{sub 2}Te{sub 3}. The lower Einstein temperature of Bi-Bi relative to Sb-Sb is consistent with the lower value of thermal conductivity of Bi{sub 2}Te{sub 3} relative to Sb{sub 2}Te{sub 3}.« less