scholarly journals Elastic stiffness coefficients of thiourea from thermal diffuse scattering

2021 ◽  
Vol 54 (1) ◽  
pp. 287-294
Author(s):  
Julia Büscher ◽  
Alessandro Mirone ◽  
Michał Stękiel ◽  
Dominik Spahr ◽  
Wolfgang Morgenroth ◽  
...  
Keyword(s):  
Diffuse Scattering ◽  
High Energy ◽  
Elastic Stiffness ◽  
Thermal Diffuse Scattering ◽  
X Ray ◽  
Stiffness Coefficients ◽  
Large Samples ◽  
Elastic Stiffness Tensor ◽  
Thermal Diffuse ◽  
Good Agreement

The complete elastic stiffness tensor of thiourea has been determined from thermal diffuse scattering (TDS) using high-energy photons (100 keV). Comparison with earlier data confirms a very good agreement of the tensor coefficients. In contrast with established methods to obtain elastic stiffness coefficients (e.g. Brillouin spectroscopy, inelastic X-ray or neutron scattering, ultrasound spectroscopy), their determination from TDS is faster, does not require large samples or intricate sample preparation, and is applicable to opaque crystals. Using high-energy photons extends the applicability of the TDS-based approach to organic compounds which would suffer from radiation damage at lower photon energies.

Lattice dynamics and elasticity of SrCO3

2016 ◽  
Vol 49 (6) ◽  
pp. 1982-1990 ◽  
Author(s):  
Tra Nguyen-Thanh ◽  
Alexei Bosak ◽  
Johannes D. Bauer ◽  
Rita Luchitskaia ◽  
Keith Refson ◽  
...  
Keyword(s):  
Lattice Dynamics ◽  
Diffuse Scattering ◽  
Density Functional ◽  
Elastic Stiffness ◽  
Theory Model ◽  
Thermal Diffuse Scattering ◽  
X Ray ◽  
The Density Functional Theory ◽  
Scattering Maps ◽  
Thermal Diffuse

The lattice dynamics and elasticity of synthetic SrCO3have been investigated by a combination ofab initiolattice dynamics calculations, microcalorimetry, Raman spectroscopy, X-ray thermal diffuse scattering and high-resolution inelastic X-ray scattering. The results of density functional based calculations were in all cases in good agreement with experiment. For the spectroscopic investigations, peak positions and intensities are well reproduced by the density functional theory model. Experimentally determined intensity distributions in thermal diffuse scattering maps differ from the theoretical distribution only in the (HK0) plane, a fact that is attributed to stacking disorder. As the model is accurate and reliable, the complete elastic stiffness tensor is predicted and, on the basis of these results, the anisotropy of the sound velocities is discussed, also in relation to the anisotropy in other carbonate systems.

Diffraction Pattern Caused by X-Ray Thermal Diffuse Scattering in Absorbing Perfect Crystal

1988 ◽  
Vol 57 (2) ◽  
pp. 524-534 ◽  
Author(s):  
Yasuji Kashiwase ◽  
Masahiro Mori ◽  
Motokazu Kogiso ◽  
Masayuki Minoura ◽  
Satoshi Sasaki
Keyword(s):  
Diffraction Pattern ◽  
Diffuse Scattering ◽  
Perfect Crystal ◽  
Thermal Diffuse Scattering ◽  
X Ray ◽  
Thermal Diffuse

Practical Aspects of Removing the Effects of Elastic and Thermal Diffuse Scattering from Spectroscopic Data for Single Crystals

2014 ◽  
Vol 20 (4) ◽  
pp. 1078-1089 ◽  
Author(s):  
Nathan R. Lugg ◽  
Melissa J. Neish ◽  
Scott D. Findlay ◽  
Leslie J. Allen
Keyword(s):  
Factor Analysis ◽  
Energy Loss ◽  
Single Crystals ◽  
Electron Energy ◽  
Diffuse Scattering ◽  
Energy Dispersive ◽  
Thermal Diffuse Scattering ◽  
X Ray ◽  
Electron Energy Loss ◽  
Thermal Diffuse

AbstractA method to remove the effects of elastic and thermal diffuse scattering (TDS) of the incident electron probe from electron energy-loss and energy-dispersive X-ray spectroscopy data for atomically resolved spectrum images of single crystals of known thickness is presented. By calculating the distribution of the probe within a specimen of known structure, it is possible to deconvolve the channeling of the probe and TDS from experimental data by reformulating the inelastic cross-section as an inverse problem. In electron energy-loss spectroscopy this allows valid comparisons with first principles fine-structure calculations to be made. In energy-dispersive X-ray spectroscopy, direct compositional analyses such as ζ-factor and Cliff–Lorimer k-factor analysis can be performed without the complications of channeling and TDS. We explore in detail how this method can be incorporated into existing multislice programs, and demonstrate practical considerations in implementing this method using a simulated test specimen. We show the importance of taking into account the scattering of the probe in k-factor analysis in a zone axis orientation. The applicability and limitations of the method are discussed.

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