Search results for "ALLOYS"
showing 10 items of 1689 documents
Bias and humidity effects on the ammonia sensing of perylene derivative/lutetium bisphthalocyanine MSDI heterojunctions
2016
International audience; In this paper, we prepared and studied sensors based on Molecular Semiconductor-Doped Insulator (MSDI) heterojunctions. These original devices are built with two stacked layers of molecular materials and exhibit very specific electrical and sensing properties. We studied the properties of a MSDI composed of the perylenetetracarboxylic dianhydride, PTCDA, or the fluorinated perylenebisimine derivative, C4F7-PTCDI, as n-type molecular material sublayers, and LuPc2 as a p-type semiconductor top layer. Their response to ammonia was compared to that of a resistor formed of only the top layer of the MSDI (LuPc2). Ammonia increases the current in the MSDIs whereas it causes…
The financial impact of Spanish pension reform: A quick estimate
2012
In this paper, we present a preliminary estimate of the financial impact of the recent reform of the Spanish pension system. After updating the projections of pension expenditure constructed in de la Fuente and Doménech (2010) for the period 2008-2060, we analyze the impact on this variable of raising the retirement age from 65 to 67 years, extending from 15 to 25 years the period over which wages are averaged to calculate the starting pension and increasing from 35 to 37 the number of contribution years required to obtain a 'full pension.' Conditional on a series of assumptions about the evolution of employment, productivity and demographics, our estimates suggest that these measures will …
Synergistic assembly of hyperbranched polyethylenimine and fatty acids leading to unusual supramolecular nanocapsules
2005
Self-assembly of hyperbranched polyethylenimine (PEI) and fatty acids leads to supramolecular inverted micellar structures that are able to irreversibly transfer water-soluble guest molecules into organic solvents. Perez Prieto, Julia, Julia.Perez@uv.es ; Stiriba, Salah Eddine, Salah.Stiriba@uv.es
Open-shell doublet character in a hexaazatrinaphthylene trianion complex
2015
Three-electron reduction of hexaazatrinaphthylene (HAN) with a magnesium(I) reagent leads to [(HAN){Mg(nacnac)}3] (1), containing a [HAN]3– ligand with a spin of S = ½. Ab initio calculations reveal that the [HAN]3– ligand in 1 has a groundstate wave function with multiconfigurational properties, and can be described as a triradicaloid species with a small amount of open-shell doublet character. peerReviewed
Ball-milling and AlB2 addition effects on the hydrogen sorption properties of the CaH2 + MgB2 system
2011
Abstract Among the borohydrides proposed for solid state hydrogen storage, Ca(BH 4 ) 2 is particularly interesting because of its favourable thermodynamics and relatively cheap price. Composite systems, where other species are present in addition to the borohydride, show some advantages in hydrogen sorption properties with respect to the borohydrides alone, despite a reduction of the theoretical storage capacity. We have investigated the milling time influence on the sorption properties of the CaH 2 + MgB 2 system from which Ca(BH 4 ) 2 and MgH 2 can be synthesized by hydrogen absorption process. Manometric and calorimetric measurements showed better kinetics for long time milled samples. …
Guest exchange in dimeric capsules of a tetraurea calix[4]arene in the solid state
2007
A solid powder of hydrogen bonded dimers of a tetraurea calix[4]arene is able to exchange the encapsulated guest in contact with the vapor of a second guest. The molecules of a guest-free powder obtained from a polar solvent cannot rearrange in the solid phase to form new guest-filled capsules under these conditions.
Hybrid molecular magnets incorporating organic donors and other electroactive molecules
1999
Molecule-based bidimensional ferromagnets can be used as anionic hosts for electroactive molecules, with the aim of obtaining multiproperty materials exhibiting in addition to the cooperative magnetism other interesting properties according to the nature of the inserted molecules. In particular, hybrid molecular compounds containing conducting (TTF-type organic donors), bi-stable or non-linear optical species are reported.
Molecular hybrids formed by oxalate bridged dinuclear anions and organometallic cations
1999
Abstract The syntheses, magnetic properties and infrared spectra of a new series of molecular hybrids formed by association of two magnetic sublattices: (i) oxalate bridged dinuclear anions [V 2 O 2 (ox)(NCS) 6 ] 4− and [M′M′'(ox)(NCS) 8 ] 4 ( M′= Fe III , Cr III ; M′' - Fe III , Cr III ; ox 2 = C 2 O 4 2 and (ii) decamethylferrocenium organometallic cation are presented. The crystal structure of [Fe(Cp * ) 2 ][(C 2 H 5 ) 4 N] 2 [V 2 O 2 (ox)(NCS) 6 ] is also discussed.
Hybrid functional study of structural, electronic and magnetic properties of S-doped ZnO with and without neutral vacancy
2013
Abstract The structural and electronic properties of S-doped ZnO are investigated by density functional theory (DFT) and empirical pseudopotential method (EPM). Using the Heyd–Scuseria–Ernzerhof (HSE) hybrid functional with an adjusted mixing coefficient α , we obtain a good agreement on lattice parameters and band gap energy with the available experimental data. We have also investigate the Zn-vacancy effects on the electronic and magnetic properties of S-doped ZnO. Our calculations demonstrate that S impurity prefers to be close to the cation vacancy in the apical position. The magnetic analysis with the HSE functional shows a triplet state character with a total magnetic moment of 1.81 μ…
Magnetoresistance studies of the ferromagnetic molecular metal (BEDT-TTF)3[MnCr(C2O4)3] under pressure
2003
(BEDT-TTF)3[MnCr(C2O4)3] is the first ferromagnetic molecular metal, in which organic layers of BEDT-TTF alternate with infinite layers of the bimetallic oxalate complex [MnCr(C2O4)3]-. While the bimetallic layer undergoes a magnetic phase transition into a canted ferromagnetic state at 5.5 K, the metallic character of the conductivity is not affected by the magnetic transition [Nature 408 (2000) 447]. We performed magnetoresistance measurements (B≤17 T) at low temperatures (T≥900 mK) and under hydrostatic pressures of up to 2.0 GPa. Oscillations in the magnetoresistance develop under pressure that can be interpreted as Shubnikov-de Haas oscillations, if an internal magnetic field is taken …