scholarly journals Competing orbital ordering inRVO3compounds: High-resolution x-ray diffraction and thermal expansion

2007 ◽  
Vol 76 (19) ◽  
Author(s):  
M. H. Sage ◽  
G. R. Blake ◽  
C. Marquina ◽  
T. T. M. Palstra
Keyword(s):  
Thermal Expansion ◽  
High Resolution ◽  
Orbital Ordering ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals An examination of the thermal expansion of urea using high-resolution variable-temperature X-ray powder diffraction

2005 ◽  
Vol 38 (6) ◽  
pp. 1038-1039 ◽  
Author(s):  
Robert Hammond ◽  
Klimentina Pencheva ◽  
Kevin J. Roberts ◽  
Patricia Mougin ◽  
Derek Wilkinson
Keyword(s):  
Thermal Expansion ◽  
High Resolution ◽  
Variable Temperature ◽  
X Ray Diffraction ◽  
Polymorphic Transformations ◽  
X Ray ◽  
Thermal Expansion Coefficients ◽  
Cell Dimensions ◽  
Expansion Coefficients ◽  
Unit Cell Dimensions

Variable-temperature high-resolution capillary-mode powder X-ray diffraction is used to assess changes in unit-cell dimensions as a function of temperature over the range 188–328 K. No evidence was found for any polymorphic transformations over this temperature range and thermal expansion coefficients for urea were found to be αa= (5.27 ± 0.26) × 10−5 K−1and αc= (1.14 ± 0.057) × 10−5 K−1.

Thermal expansion of single-crystalline β-Ga2O3 from RT to 1200 K studied by synchrotron-based high resolution x-ray diffraction

2018 ◽  
Vol 113 (18) ◽  
pp. 182102 ◽  
Author(s):  
Zongzhe Cheng ◽  
Michael Hanke ◽  
Zbigniew Galazka ◽  
Achim Trampert
Keyword(s):  
Thermal Expansion ◽  
High Resolution ◽  
X Ray Diffraction ◽  
Single Crystalline ◽  
X Ray

Variation of cation distribution with temperature and its consequences on thermal expansion for Ca3Eu2(BO3)4

2020 ◽  
Vol 76 (4) ◽  
pp. 554-562
Author(s):  
Katarzyna M. Kosyl ◽  
Wojciech Paszkowicz ◽  
Alexey N. Shekhovtsov ◽  
Miron B. Kosmyna ◽  
Jerzy Antonowicz ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
High Resolution ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lattice Constants ◽  
Thermal Expansion Anisotropy ◽  
Structural Details

The structure of calcium europium orthoborate, Ca3Eu2(BO3)4, was determined using high-resolution powder X-ray diffraction data collected at the ID22 beamline (ESRF) under ambient conditions, as well as at high temperature. Rietveld refinement allowed determination of the lattice constants and structural details, including the Ca/Eu ratios at the three cationic sites and their evolution with temperature. Clear thermal expansion anisotropy was found, and slope changes of lattice-constant dependencies on temperature were observed at 923 K. Above this temperature the changes in occupation of the Ca/Eu sites occur, exhibiting a tendency towards a more uniform Eu distribution over the three Ca/Eu sites. Possible structural origins of the observed thermal expansion anisotropy are discussed.

scholarly journals Thermal expansion in BaRuO3 perovskites – an unusual case of bond strengthening at high temperatures

2017 ◽  
Vol 46 (9) ◽  
pp. 2974-2980 ◽  
Author(s):  
Paula Kayser ◽  
Sean Injac ◽  
Brendan J. Kennedy ◽  
Andre L. Menezes de Oliveira ◽  
Yuichi Shirako ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
High Resolution ◽  
High Temperatures ◽  
Room Temperature ◽  
Unusual Case ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Dependences

The temperature dependences of the structures of three polytypes of BaRuO3 have been investigated between room temperature and 1000 °C using high resolution synchrotron X-ray diffraction.

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

Tubulin structure at intermediate resolution

1995 ◽  
Vol 53 ◽  
pp. 852-853
Author(s):  
K. H. Downing ◽  
S. G. Wolf ◽  
E. Nogales
Keyword(s):  
High Resolution ◽  
Structural Data ◽  
Therapeutic Drug ◽  
Zinc Ions ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Negative Stain ◽  
Functional Mechanisms ◽  
Tubulin Structure

Microtubules are involved in a host of critical cell activities, many of which involve transport of organelles through the cell. Different sets of microtubules appear to form during the cell cycle for different functions. Knowledge of the structure of tubulin will be necessary in order to understand the various functional mechanisms of microtubule assemble, disassembly, and interaction with other molecules, but tubulin has so far resisted crystallization for x-ray diffraction studies. Fortuitously, in the presence of zinc ions, tubulin also forms two-dimensional, crystalline sheets that are ideally suited for study by electron microscopy. We have refined procedures for forming the sheets and preparing them for EM, and have been able to obtain high-resolution structural data that sheds light on the formation and stabilization of microtubules, and even the interaction with a therapeutic drug.Tubulin sheets had been extensively studied in negative stain, demonstrating that the same protofilament structure was formed in the sheets and microtubules. For high resolution studies, we have found that the sheets embedded in either glucose or tannin diffract to around 3 Å.

Sign in / Sign up

Export Citation Format

Share Document