Gianluca Paglia

Quantitative size-dependent structure and strain determination of CdSe nanoparticles using atomic pair distribution function analysis

The size-dependent structure of CdSe nanoparticles, with diameters ranging from

Structural characterization of the clay mineral illite-1M

2\phantom{\rule{0.3em}{0ex}}\text{to}\phantom{\rule{0.3em}{0ex}}4\phantom{\rule{0.3em}{0ex}}\mathrm{nm}

Fine-Scale Nanostructure in γ-Al2O3

, has been studied using the atomic pair distribution function (PDF) method. The core structure of the measured CdSe nanoparticles can be described in terms of the wurtzite atomic structure with extensive stacking faults. The density of faults in the nanoparticles is

Structures of Alkali Metals in Silica Gel Nanopores: New Materials for Chemical Reductions and Hydrogen Production

\ensuremath{\sim}50%

Accurate Structure Determination of Mo6SyIz Nanowires from Atomic Pair Distribution Function (PDF) Analysis

. The diameter of the core region was extracted directly from the PDF data and is in good agreement with the diameter obtained from standard characterization methods, suggesting that there is little surface amorphous region. A compressive strain was measured in the Cd--Se bond length that increases with decreasing particle size being 0.5% with respect to bulk CdSe for the

Utilizing total scattering to study the Jahn-Teller transition in La 1-x Ca x MnO 3

2\phantom{\rule{0.3em}{0ex}}\mathrm{nm}

Utilizing total scattering to study the Jahn-Teller transition in La{sub 1-x}Ca{sub x}MnO{sub 3}.

diameter particles. This study demonstrates the size-dependent quantitative structural information that can be obtained even from very small nanoparticles using the PDF approach.

Accurate structure and size determination of CdSe nanoparticles using PDF analysis

This work reports the structural characterization of illite-1M from northern Hungary, with the first attempt to refine the structure model and locate the interlayer water molecule. Structural characterization was accomplished using state-of-the-art analytical methods available for clays. The results illustrate the status of techniques for clay structure determination, as well as providing a structural model for illite. The chemical formula for the illite-1M under investigation can be written as K0.78Ca0.02Na0.02(Mg0.34Al1.69FeIII0.02)[Si3.35Al0.65]O10(OH)2·nH2O. Structure simulations with WILDFIRE yielded a model with 30% of cis-vacant layers and an expandability percentage of 10%. The value of the percentage of expandability was confirmed with NEWMOD, with which the best simulation was obtained with 90% of di-octahedral mica with K (80% site population) in the interlayer region and 10% of expandable layers. The best structure simulation obtained with DIFFaX was also obtained with a population of K atoms of 80%, six cells along c (in agreement with the results of a transmission electron microscopy study) and an average dimension of the particles in the ab plane of 300 nm. Besides the determination of the basic structure unit (the results are consistent with those obtained with the local information provided by a fit of the pair distribution function data) and the model of disorder, refinement with DIFFaX+ allowed the calculation of a possible position for the interlayer water molecule. Although physically sound, both the observed tetrahedral layer corrugation and the location of the water molecule need further experimental evidence, because the final fit of the observed pattern is still imperfect. The reasons for this misfit are discussed.