![](/images/tempism/analisi/microscopia/imperatori/xrd1.png)
nλ = 2 dsin Θ
where n is an integer (1, 2, 3, ...), λ is the wavelength of the incident x-ray wave, d the lattice plane spacing andΘ the angle of incidence and reflection to the planes. Since every crystalline phase has a characteristic set of lattice spacings, the phases present in the specimen can be identified.
TECHNICAL SPCIFICATIONS
Seifert XRD 3003 TT
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Two circle goniometer in symmetrical or asymmetrical Theta-Theta configuration. Angle scans are perfomed by X-ray source and detector (Theta-Theta scans), with the sample fixed in horizontal position. The reproducibility is ±0.0003°.
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The diffractometer is equipped with a thin film attachment, consisting of long Soller slits and a flat graphite monochromator, for grazing incidence measurements.
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NaI scintillation counter.
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Cu Kα radiation (λ = 1.5418 Å)
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Two circle goniometer in the Bragg-Brentano geometry, with a secondary curved graphite monochromator.
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Cu-ka radiation (λ = 1.5418 Å) is employed..
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Coupled or independent Omega/2Theta scans are possible.
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A carousel with 12 sample-holders allows a sequence of measurements.
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NaI scintillation counter.
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Rayflex commercial software
AVAILABLE TECHNIQUES
- Normal and grazing incidence X-ray diffraction from polycrystalline powders and films.
- Qualitative and quantitative phase analysis.
- Structural and microstructural analysis: lattice parameters, crystallite sizes, microstrain, texture.
- Rietveld refinements.
- ab-initio methods to solve structures.
SAMPLE
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Crystalline powders and films
USE FOR
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Metals
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Semiconductors
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Alloys
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Catalysis
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Pharmaceuticals
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Cultural heritages
Case Studies
Nanocluster superstructures or nanoparticles?
The self-consuming scaffold decides
We show that using the same reaction procedure, by hindering or allowing the formation of a reaction intermediate, the Ag+dodecanethiolate polymeric complex, it is possible to selectively obtain Ag dodecanethiolate nanoparticles or Ag dodecanethiolate nanoclusters.
The XRD patterns of the nanoclusters present a sequence of equally spaced low angles peaks, which indicate the presence of a lamellar structure. The presence of low-angle peaks has been attributed to a cluster superlattice, whose d spacing is smaller than that of the corresponding pristine Ag+ thiolate complex, probably due to interdigitation.
The superstructure influences the chemical–physical properties such as luminescence in both the UV and NIR regions or the conductivity.
See: L. Suber, P. Imperatori et al., Nanoscale 10, 7472 (2018).
![](/images/tempism/analisi/microscopia/imperatori/caso1a_b.png)
![](/images/tempism/analisi/microscopia/imperatori/caso2.png)
Tuning hard and soft magnetic FePt nanocomposites
Nanocomposites formed by hard and soft magnetic phases are very promising for magnetic energy storage and biomedical applications. Mainly depending on Fe:Pt atomic ratio, multi-phase or single phase FePt nanocomposites have been prepared by thermal treatment of core shell FePt(Ag)@Fe3O4 nanoparticles at 750°C for 1 h under flow of a Ar + 5% H2 gas mixture.2.
Performing Rietveld refinement of the XRD data the different phases have been singled out.
Besides single phase hard L10 FePt
and soft magnetic L12 2 Fe3Pt nanoparticles;
two phase soft α-FePt and ɣ-FePt
and hard and soft magnetic L10 FePt and soft L12 FePt3.
Nanocomposites have been formed and the structure and morphology correlated to their magnetic behavior.
See: L. Suber, P. Imperatori et al., J. Alloys Comp. 663, 601 (2016).