Determination of Shell Thickness of Spherical Core-Shell NixMn1-x(OH)2Particles via Absorption Calculations of X-Ray Diffraction Patterns

2014 ◽  
Vol 161 (5) ◽  
pp. A814-A820 ◽  
Author(s):  
J. Camardese ◽  
E. McCalla ◽  
D. W. Abarbanel ◽  
J. R. Dahn
Keyword(s):  
Shell Thickness ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spherical Core ◽  
Diffraction Patterns

scholarly journals Born out of Fire and Ice: Polymorph Studies of the Antiviral Famciclovir

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 129
Author(s):  
Liana Vella-Zarb ◽  
Ulrich Baisch
Keyword(s):  
Variable Temperature ◽  
Chemical Properties ◽  
Crystal Form ◽  
X Ray Diffraction ◽  
Crystal Forms ◽  
X Ray ◽  
Physical Chemical ◽  
Diffraction Patterns ◽  
Crystalline Forms

There is much interest and focus on solid forms of famciclovir. However, in spite of the abundance of reported differences in oral bioavailability, compressibility, and other physical–chemical properties of the various crystal forms of this drug, very little precise structural analysis is available in the literature to date. The form used in the commercial formulation is the anhydrous form I. Patents and patent applications report three different anhydrous crystalline forms on the basis of unindexed powder diffraction patterns. Single-crystal and variable-temperature X-ray diffraction experiments using the commercially available anhydrous form of famciclovir were carried out and led not only to the crystal structure determination of the anhydrous form I, but also to discovery of a new crystal form of anhydrous famciclovir from powder data.

scholarly journals Synthesis of the Modifications of Ca2SiO4 and the Determination of their Powder X-ray Diffraction Patterns

1963 ◽  
Vol 71 (806) ◽  
pp. 63-68 ◽  
Author(s):  
Goro YAMAGUCHI ◽  
Yoshio ONO ◽  
Shigeo KAWAMURA ◽  
Yoshiaki SODA
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns

Design and Functionalization of Magnetic Core-Shell Oxide Nanoparticles Exhibiting Exchange Bias Features

2011 ◽  
Vol 1359 ◽  
Author(s):  
Fayna Mammeri ◽  
Faïza Mamèche ◽  
Zeinab Kataya ◽  
Nader Yaacoub ◽  
Anna Slawska-Waniewska ◽  
...  
Keyword(s):  
Exchange Bias ◽  
Shell Thickness ◽  
Magnetic Core ◽  
Oxide Nanoparticles ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Microstructural Characteristics ◽  
X Ray ◽  
Transmission Electron ◽  
Structural And Magnetic Properties

ABSTRACTCore-shell magnetic nanoparticles (CSNPs) composed of a ferrimagnetic core (CoFe2O4) embedded in an antiferromagnetic shell (CoO) were produced using seed mediated growth in a polyol. Different core sizes and shell thicknesses were considered. The structural and magnetic properties of assemblies of these nanoparticles were characterized by means of X-ray Diffraction, Transmission Electron Microscopy, dc-magnetometry (SQUID) and 57Fe Mössbauer spectrometry. The measured EB magnetic field values, at low temperature, are found to be weak whatever the microstructural characteristics of the studied CSMNPs. Simultaneously, both the magnetization and the interparticle interaction (mainly dipolar) appear clearly reduced when the shell thickness increases.

scholarly journals X-Ray Diffraction from Magnetically Oriented Microcrystal Suspension

2014 ◽  
Vol 70 (a1) ◽  
pp. C1136-C1136
Author(s):  
Kazuaki Aburaya ◽  
Chiaki Tsuboi ◽  
Fumiko Kimura ◽  
Kenji Matsumoto ◽  
Masataka Maeyama ◽  
...  
Keyword(s):  
Single Crystal ◽  
Magnetic Circuit ◽  
X Ray Diffraction ◽  
Glass Capillary ◽  
Uv Curable ◽  
X Ray ◽  
Novel Method ◽  
Diffraction Patterns ◽  
Magnetic Field Generator

A three dimensionally magnetically oriented microcrystal array (3D-MOMA) is attractive to determination of a crystal structure as well as a molecular structure because it does not require a single crystal with sufficient size and quality for diffraction studies. We have developed a novel method to fabricate 3D-MOMA and determined several crystal structures using the 3D-MOMAs[1],[2]. However, the structure determination through MOMA requires a solidification treatment with UV curable monomer prior to X-ray diffraction experiment. We have developed a new X-ray diffractometer equipped with a magnetic field generator, which makes it possible to collect diffraction data without the solidification treatment. In this poster, we describe X-ray diffraction analyses of a magnetically oriented microcrystal suspension (MOMS) of L-alanine without the solidification treatment. A suspension of L-alanine microcrystals was poured in a glass capillary and rotated at a constant speed in a magnetic circuit attached in the X-ray diffractometer. Then, diffraction images were collected every 60 seconds. In the initial phase, the diffraction pattern showed a broad shape similar to that from a powder sample. As time goes on, diffraction patterns have gradually changed to single-crystal like patterns. After 2 hours, the shape of diffraction spots became as sharp as that of a single crystal. This observation shows that the microcrystals are oriented in the same direction. Owing to the improvement of the magnetic circuit and X-ray diffractometer, the quality of the diffraction has been greatly improved compared to that reported previously[3]. Further details of the analyses will be shown in the poster.

Structure determination of forms I and II of phenobarbital from X-ray powder diffraction

2005 ◽  
Vol 61 (1) ◽  
pp. 80-88 ◽  
Author(s):  
Cyril Platteau ◽  
Jacques Lefebvre ◽  
Stephanie Hemon ◽  
Carsten Baehtz ◽  
Florence Danede ◽  
...  
Keyword(s):  
X Ray Diffraction ◽  
Rietveld Refinements ◽  
Space Group ◽  
X Ray ◽  
Bragg Peak Profiles ◽  
Monte Carlo Simulated Annealing ◽  
Crystal Structural ◽  
Diffraction Patterns ◽  
Annealing Method

From pure powders of forms I and II of phenobarbital, X-ray diffraction patterns were recorded at room temperature. The starting crystal structural models were found by a Monte-Carlo simulated annealing method. The structures of the two forms were obtained through Rietveld refinements. Soft restraints were applied on bond lengths and bond angles, all H-atom positions were calculated. The cell of form I is monoclinic with the space group P21/n, Z = 12, Z′ = 3. Form II has a triclinic cell, with the space group P\bar 1, Z = 6, Z′ = 3. For both forms, the crystal cohesion is achieved by networks of N—H...O hydrogen bonds along [101]. The broadening of the Bragg peak profiles is interpreted in terms of isotropic strain effects and anisotropic size effects.

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