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

Title: Pair distribution functions of amorphous organic thin films from synchrotron X-ray scattering in transmission mode

Abstract

Using high-brilliance high-energy synchrotron X-ray radiation, for the first time the total scattering of a thin organic glass film deposited on a strongly scattering inorganic substrate has been measured in transmission mode. The organic thin film was composed of the weakly scattering pharmaceutical substance indomethacin in the amorphous state. The film was 130 µm thick atop a borosilicate glass substrate of equal thickness. The atomic pair distribution function derived from the thin-film measurement is in excellent agreement with that from bulk measurements. This ability to measure the total scattering of amorphous organic thin films in transmission will enable accurate in situ structural studies for a wide range of materials.

Authors:
; ORCiD logo; ; ORCiD logo
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1368629
Grant/Contract Number:
AC02-06CH11357
Resource Type:
Journal Article: Published Article
Journal Name:
IUCrJ
Additional Journal Information:
Journal Volume: 4; Journal Issue: 5; Related Information: CHORUS Timestamp: 2017-09-01 11:28:40; Journal ID: ISSN 2052-2525
Publisher:
International Union of Crystallography (IUCr)
Country of Publication:
United Kingdom
Language:
English

Citation Formats

Shi, Chenyang, Teerakapibal, Rattavut, Yu, Lian, and Zhang, Geoff G. Z. Pair distribution functions of amorphous organic thin films from synchrotron X-ray scattering in transmission mode. United Kingdom: N. p., 2017. Web. doi:10.1107/S2052252517009344.
Shi, Chenyang, Teerakapibal, Rattavut, Yu, Lian, & Zhang, Geoff G. Z. Pair distribution functions of amorphous organic thin films from synchrotron X-ray scattering in transmission mode. United Kingdom. doi:10.1107/S2052252517009344.
Shi, Chenyang, Teerakapibal, Rattavut, Yu, Lian, and Zhang, Geoff G. Z. Mon . "Pair distribution functions of amorphous organic thin films from synchrotron X-ray scattering in transmission mode". United Kingdom. doi:10.1107/S2052252517009344.
@article{osti_1368629,
title = {Pair distribution functions of amorphous organic thin films from synchrotron X-ray scattering in transmission mode},
author = {Shi, Chenyang and Teerakapibal, Rattavut and Yu, Lian and Zhang, Geoff G. Z.},
abstractNote = {Using high-brilliance high-energy synchrotron X-ray radiation, for the first time the total scattering of a thin organic glass film deposited on a strongly scattering inorganic substrate has been measured in transmission mode. The organic thin film was composed of the weakly scattering pharmaceutical substance indomethacin in the amorphous state. The film was 130 µm thick atop a borosilicate glass substrate of equal thickness. The atomic pair distribution function derived from the thin-film measurement is in excellent agreement with that from bulk measurements. This ability to measure the total scattering of amorphous organic thin films in transmission will enable accurate in situ structural studies for a wide range of materials.},
doi = {10.1107/S2052252517009344},
journal = {IUCrJ},
number = 5,
volume = 4,
place = {United Kingdom},
year = {Mon Jul 10 00:00:00 EDT 2017},
month = {Mon Jul 10 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1107/S2052252517009344

Save / Share:
  • Using high-brilliance high-energy synchrotron X-ray radiation, for the first time the total scattering of a thin organic glass film deposited on a strongly scattering inorganic substrate has been measured in transmission mode. The organic thin film was composed of the weakly scattering pharmaceutical substance indomethacin in the amorphous state. The film was 130 µm thick atop a borosilicate glass substrate of equal thickness. The atomic pair distribution function derived from the thin-film measurement is in excellent agreement with that from bulk measurements. This ability to measure the total scattering of amorphous organic thin films in transmission will enable accuratein situstructuralmore » studies for a wide range of materials.« less
  • A new method is developed to study the atomic structure of layered materials by a two-dimensional atomic pair distribution function (2D-PDF) analysis. Using synchrotron x-ray scattering, this method is applied to the study of an Al[sub 65]Cu[sub 15]Co[sub 20] single decagonal quasicrystal. The obtained 2D-PDF's are in excellent agreement with those calculated from a recently proposed structure model based on decagonal cluster packing. However, additional short-range structure is found by analyzing the diffuse scattering intensity. A modification of the model is proposed to explain this short-range structure.
  • For many years, the idea of analyzing atom-atom contacts in amorphous drug-polymer systems has been of major interest, because this method has always had the potential to differentiate between amorphous systems with domains and amorphous systems which are molecular mixtures. In this study, local structure of ionic and noninonic interactions were studied by High-Energy X-ray Diffraction and Pair Distribution Function (PDF) analysis in amorphous solid dispersions of lapatinib in hypromellose phthalate (HPMCP) and hypromellose (HPMC-E3). The strategy of extracting lapatinib intermolecular drug interactions from the total PDF x-ray pattern was successfully applied allowing the detection of distinct nearest neighbor contactsmore » for the HPMC-E3 rich preparations showing that lapatinib molecules do not cluster in the same way as observed in HPMC-P, where ionic interactions are present. Orientational correlations up to nearest neighbor molecules at about 4.3 Å were observed for polymer rich samples; both observations showed strong correlation to the stability of the systems. Lasty, the superior physical stability of 1:3 LP:HPMCP was consistent with the absence of significant intermolecular interactions in (ΔD inter LP(r)) in the range of 3.0 to 6.0 Å, which are attributed to C-C, C-N and C-O nearest neighbor contacts present in drug-drug interactions.« less
  • A review is presented of recent research into imaging on different length scales of defect structures in wide band gap semiconductors. This includes: synchrotron white beam X-ray topography (SWBXT) imaging of defects in SiC wafers and epilayers; high-resolution X-ray diffraction (HRXRD) and high-resolution transmission electron microscopy (HRTEM) studies of strain relaxation in AlN and GaN epilayers on on-axis and vicinal SiC and sapphire substrates; TEM studies of fault structures in GaN/AlN films on SiC substrates; and TEM studies of threading dislocation density reduction driven by growth mode modification in AlN films grown on sapphire substrates. In detail, studies of closed-coremore » and hollow-core screw dislocations, basal plane dislocations and stacking faults (SFs) in 4H- and 6H-SiC substrates and films are presented. The mechanism of improved mismatch strain relaxation associated with the growth of GaN (AlN) films on vicinal substrates is discussed. This is attributed to the combined effects of mutual tilt between the epilayer and the substrate, which helps to relax out-of-plane mismatch, and by the generation of geometric partial misfit dislocations (GPMDs), which serves both to relax in-plane mismatch and accommodate stacking differences between the epilayer and substrate at some proportion of the steps at the substrate/film interface. In addition, the formation mechanisms of intersecting SF structures observed in GaN/AlN/SiC epilayers are presented. These fault structures comprise SFs that fold back and forth from the basal plane (I1 Basal Plane Faults; BSFs) to the prismatic plane (Prismatic Stacking Faults; PSFs). Finally, the threading dislocation density reduction in AlN/sapphire films is modeled based on overgrowth of the dislocation outcrops by macrosteps which appear during a transition from step flow to 2D layer-by-layer growth.« less