Static and dynamic atom displacements in nanocrystalline powders from diffraction analysis at finite temperature

Name: Static and dynamic atom displacements in nanocrystalline powders from diffraction analysis at finite temperature
Author: Ozturk, Hande, Erucar, Ilknur, Batyrow, Merdan

İsim	Static and dynamic atom displacements in nanocrystalline powders from diffraction analysis at finite temperature
Yazar	Ozturk, Hande, Erucar, Ilknur, Batyrow, Merdan
Basım Tarihi:	2024-05
Basım Yeri	- Elsevier
Konu	Rietveld refinement, Thermal diffuse scattering, Molecular dynamics simulations, Size effects, X-ray diffraction, Nanoparticles
Tür	Süreli Yayın
Dil	İngilizce
Dijital	Evet
Yazma	Hayır
Kütüphane:	Özyeğin Üniversitesi
Demirbaş Numarası	2589-1529
Kayıt Numarası	3d56ed9b-8b92-4abb-8c80-caef58853c48
Lokasyon	Mechanical Engineering, Natural and Mathematical Sciences
Tarih	2024-05
Notlar	TÜBİTAK
Örnek Metin	We evaluate the accuracy of x-ray diffraction analysis performed by Rietveld refinement in extracting the static and dynamic atomic displacement parameters of spherical gold nanocrystals with sizes of 30 nm and below and within a temperature interval of 10-300 K. A self-consistent computational workflow composed of real- and reciprocal- space analyses is designed for this purpose. We obtain average lattice parameters, static and thermal atomic displacements as well as their temperature and particle size dependence in an ideally monodispersed and realistic nanocrystalline powder generated by molecular dynamics simulations. Then, we compare crystallographic parameters obtained from real- and reciprocal- space analyses to evaluate the accuracy of diffraction analysis. We also extend the comparison to local variations of crystallographic parameters in the nanocrystals and show how Rietveld refinement relates to the average parameters of the core and surface regions separately. We show that 1) average lattice parameters obtained from Rietveld refinement are greater than the mean lattice parameter of small nanocrystals and converge to the core lattice parameter with increasing particle size, 2) Rietveld refinement significantly underestimates static atom displacements of surface atoms in small nanocrystals, 3) dynamic atomic displacements in nanocrystalline gold powders are reliably obtained within 5 % error by Rietveld refinement, provided that thermal diffuse scattering is adequately removed from the diffraction data, 4) the discrepancy between real- and reciprocal-space analysis increases for the smallest gold nanocrystal.
DOI	10.1016/j.mtla.2024.102099
Cilt	34

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Static and dynamic atom displacements in nanocrystalline powders from diffraction analysis at finite temperature

Yazar Ozturk, Hande, Erucar, Ilknur, Batyrow, Merdan

Basım Tarihi 2024-05

Basım Yeri - Elsevier

Konu Rietveld refinement, Thermal diffuse scattering, Molecular dynamics simulations, Size effects, X-ray diffraction, Nanoparticles

Tür Süreli Yayın

Dil İngilizce

Dijital Evet

Yazma Hayır

Kütüphane Özyeğin Üniversitesi

Demirbaş Numarası 2589-1529

Kayıt Numarası 3d56ed9b-8b92-4abb-8c80-caef58853c48

Lokasyon Mechanical Engineering, Natural and Mathematical Sciences

Tarih 2024-05

Notlar TÜBİTAK

Örnek Metin We evaluate the accuracy of x-ray diffraction analysis performed by Rietveld refinement in extracting the static and dynamic atomic displacement parameters of spherical gold nanocrystals with sizes of 30 nm and below and within a temperature interval of 10-300 K. A self-consistent computational workflow composed of real- and reciprocal- space analyses is designed for this purpose. We obtain average lattice parameters, static and thermal atomic displacements as well as their temperature and particle size dependence in an ideally monodispersed and realistic nanocrystalline powder generated by molecular dynamics simulations. Then, we compare crystallographic parameters obtained from real- and reciprocal- space analyses to evaluate the accuracy of diffraction analysis. We also extend the comparison to local variations of crystallographic parameters in the nanocrystals and show how Rietveld refinement relates to the average parameters of the core and surface regions separately. We show that 1) average lattice parameters obtained from Rietveld refinement are greater than the mean lattice parameter of small nanocrystals and converge to the core lattice parameter with increasing particle size, 2) Rietveld refinement significantly underestimates static atom displacements of surface atoms in small nanocrystals, 3) dynamic atomic displacements in nanocrystalline gold powders are reliably obtained within 5 % error by Rietveld refinement, provided that thermal diffuse scattering is adequately removed from the diffraction data, 4) the discrepancy between real- and reciprocal-space analysis increases for the smallest gold nanocrystal.

DOI 10.1016/j.mtla.2024.102099

Cilt 34