Search results for "Metals"

Photoinduced charge transfer from Carbon Dots to Graphene in solid composite

2019

Abstract The emission in solid phase of Carbon Dots (CDs) deposited by drop-casting technique is investigated by means of micro-photoluminescence. Graphene and SiO2 are used as substrates, and the influence of their different nature – conductive or insulating – on the emission of CDs is highlighed. In particular, a systematic loss of efficiency in the emission of CDs on graphene is found, suggesting a CD-graphene interaction possibly due to a photoinduced electron transfer between the surface states of CDs and the conduction band of graphene. Finally, thanks to the negligible influence on CDs emission, SiO2 substrate is used as support to perform thermal processing of CDs in solid phase, sh…

Scaffolds based on hyaluronan crosslinked with a polyaminoacid: Novel candidates for tissue engineering application

2008

New porous scaffolds, with a suitable hydrolytic and enzymatic degradation, useful for tissue engineering applications have been obtained by a carbodiimide mediated reaction between hyaluronan (HA) and a synthetic polymer with a polyaminoacid structure such as α,β-polyaspartylhydrazide (PAHy). Scaffolds with a different molar ratio between PAHy repeating units and HA repeating units have been prepared and characterized from a chemical and physicochemical point of view. Tests of indirect and direct cytotoxicity, cell adhesion, and spreading on these biomaterials have been performed by using murine L929 fibroblasts. The new biomaterials showed a good cell compatibility and ability to allow ce…

WITHDRAWN: Ab initio calculations of SrZrO3 and PbZrO3 (001) surfaces

2010

Numerical Simulation of Turbulent Flows, Heat and Mass Transfer in Metallurgical Induction Processes

2007

Self-organization of porphyrin units induced by magnetic field during sol-gel polymerization

2007

The use of a magnetic field as a controlling factor during the hydrolysis-polycondensation of porphyrin precursors substituted by Si(OR)(3) groups, induces a self-organization of porphyrin moieties due to the stacking of these units in the hybrid material and this study also confirms the effect of the magnetic field in the nano- and micrometric organization during the kinetically controlled polycondensation process.

Photo-induced magnetic bistability in a controlled assembly of anisotropic coordination nanoparticles.

2011

International audience; Anisotropic coordination nanoparticles of the photomagnetic network Cs(I)(2)Cu(II)(7)[Mo(IV)(CN)(8)](4) are obtained through a surfactant-free high-yield synthetic procedure in water. These particles are organised as Langmuir-Blodgett films with a preferential orientation of the nano-objects within the film that exhibit a magnetic bistability below 20 K with a very large coercivity due to an efficient photo-transformation.

Pressure-induced band anticrossing in two adamantine ordered-vacancy compounds: CdGa2S4 and HgGa2S4

2021

Abstract This paper reports a joint experimental and theoretical study of the electronic band structure of two ordered-vacancy compounds with defect-chalcopyrite structure: CdGa2S4 and HgGa2S4. High-pressure optical-absorption experiments (up to around 17 GPa) combined with first-principles electronic band-structure calculations provide compelling evidence of strong nonlinear pressure dependence of the bandgap in both compounds. The nonlinear pressure dependence is well accounted for by the band anticrossing model that was previously established mostly for selenides with defect chalcopyrite structure. Therefore, our results on two sulfides with defect chalcopyrite structure under compressio…

Atomistic simulation of the [001]surface structure in BaTiO3

1997

Abstract We simulate the effect of the surface relaxation on the polarization of the layers of paraelectric phase in the vicinity of the [001] surface in BaTiO 3 in the framework of the shell-model potentials. We observe large polarization of ions in the first two layers of the surface. Our simulations confirm the possibility of existence of Ti- and Ba-containing top layers in [001] BaTiO 3 surfaces.

Band Gap Engineering and Trap Depths of Intrinsic Point Defects in RAlO3 (R = Y, La, Gd, Yb, Lu) Perovskites

2021

The work was supported by the Polish National Science Centre (Project No. 2018/31/B/ST8/00774), by the NATO SPS Project G5647, and by the Ministry of Education and Science of Ukraine (Project DB/Kinetyka no. 0119U002249). L.V. acknowledges support of the National Research Foundation of Ukraine under Grant No. 2020.02/0373 “Crystalline phosphors’ engineering for biomedical applications, energy saving lighting and contactless thermometry”. Researchers from Tartu were supported by the ERDF fundings in Estonia granted to the Centre of Excellence TK141 “Advanced materials and high-technology devices for sustainable energetics, sensorics and nanoelectronics (HiTechDevices)” (Grant No. 2014-2020.4…

Local structure and magnetization of ferromagnetic Cu-doped ZnO films: No magnetism at the dopant?

2016

Abstract Relationship between magnetism and structure of Cu-doped ZnO was investigated at macroscopic and microscopic levels. Thin Zn1−xCuxO films (x = 0.02, 0.04, 0.07 and 0.10) were prepared by a pulsed laser deposition and characterized via superconducting quantum interference device (SQUID) magnetometry, high-resolution x-ray diffraction, and Cu K-edge and Zn K-edge x-ray absorption, x-ray linear dichroism and x-ray circular magnetic dichroism spectroscopy. Even though the samples exhibit room-temperature ferromagnetism with magnetization that increases with Cu concentration, we did not detect signatures of local magnetic moments associated with Cu atoms, as evidenced by the lack of any…