Search results for " Material properties"
showing 10 items of 10 documents
Azido and thiocyanato bridged dinuclear Ni(II) complexes involving 8-aminoquinoline based Schiff base as blocking ligands: Crystal structures, ferrom…
2020
Abstract The use of two 8-aminoquinoline-based tridentate N3-donor rigid Schiff base ligands (L1 and L2) with Ni(II) in the presence of the pseudohalides, NaN3 and NaSCN results in the crystallization of the two novel Ni(II) dimers: [Ni2(L1)2(µ1,1′-N3)2(N3)2] (1) and [Ni2(L2)2(µ1,3-NCS)2(NCS)2] (2). Both complexes are centrosymmetric Ni(II) dimers where the Schiff base ligands coordinate the octahedral Ni(II) centres in a mer configuration with one terminal and two bridging pseudohalide ligands in the remaining positions. Complex 1 shows Ni(II) ions connected by a double µ1,1′-N3− bridge whereas in complex 2 the Ni(II) ions are connected by a double µ1,3-NCS− bridge. The magnetic properties…
Modelling Aspects in Accumulative Roll Bonding process by Explicit Finite Element Analysis
2013
Accumulative Roll-Bonding (ARB) process is a severe plastic deformation (SPD) process, capable of developing grains below 1 μm in diameter and improving mechanical properties of the material. In this study, the authors compared two different FE-codes with respect of its applicability for numerical analysis of the ARB process. Modelling this process was achieved using the explicit code for Abaqus/CAE both in 2D and 3D. The proposed model was used to assess the impact of ARB cycles on the final material properties. The numerical results in 2D and 3D were compared and contrasted. The research work presented in this paper is focused on the simulation optimization based on CPU time minimization.…
Stoichiometry of LiNiO2 Studied by Mössbauer Spectroscopy
2002
From the 61Ni and 57Fe Mossbauer spectroscopy data follows the cationic site assignment in Li1−x Ni1+x O2. Our data explain the ferromagnetic properties of this material because of the appearance of Ni2+ (S = 1) among Ni3+ (S = 1/2) in Ni3+O2 hexagonal planes. We have no evidence for the ferromagnetic interaction between the NiO2 layers through the excess Ni2+ ions substituting the Li+ ions. The presence of Ni2+ found in the Ni3+O2 planes explains the absence of the Jahn-Teller distortions probably because of the electronic transfer between the Ni3+ and Ni2+ ions.
Hydrogen bonding versus π-stacking in ferromagnetic interactions. Studies on a copper triazolopyridine complex
2013
Magnetic susceptibility measurements show weak ferromagnetic exchange between the copper(II) ions of a novel triazolopyridine derivative [Cu(TPT)(H2O)2(BF4)](BF4)·2H2O (TPT = 3-{6-([1,2,3]triazolo[1,5-a]pyrid-3-yl)-2-pyridyl}-[1,2,3]triazolo[1,5-a]pyridine). Mononuclear [Cu(TPT)(H2O)2(BF4)]+ entities are connected through O–H⋯F, C–H⋯F and π⋯π interactions to give a 3D framework. Ferromagnetic properties are discussed on the basis of the interactions network.
Spin-resolved unoccupied density of states in epitaxial Heusler-alloy films
2009
We investigate the electronic properties of epitaxial ${\text{Co}}_{2}({\text{Fe}}_{x}{\text{Mn}}_{1\ensuremath{-}x})\text{Si}$, ${\text{Co}}_{2}\text{Fe}({\text{Al}}_{1\ensuremath{-}x}{\text{Si}}_{x})$, and ${\text{Co}}_{2}({\text{Cr}}_{0.6}{\text{Fe}}_{0.4})\text{Al}$ films on MgO(100) substrates using circular dichroism in x-ray absorption spectroscopy (XMCD). Considering final-state electron correlations, the spin-resolved partial density of states at the Co atom can be extracted from XMCD data. The experimental results corroborate the predicted half-metallic ferromagnetic properties of these alloys and reveal a compositional dependence of the Fermi energy position within the minority b…
Synthesis, characterization and magnetism of monodispersed water soluble palladium nanoparticles
2008
Water soluble, monodispersed Pd nanoparticles with a narrow particle size distribution have been successfully synthesized by controlled reduction of [PdCl4]2−. The resulting aqueous colloids are stable over extended periods of time and can be prepared at high nanoparticle loading (20 g/L of Pd) with no agglomeration. The size of the nanoparticles can be reduced from the nanometer (ca. 3.5 nm) to the sub-nanometer size range (ca. 0.9 nm). Detailed magnetic characterization indicated that the larger, 3.5 nm nanoparticles show ferromagnetic properties at room temperature, while the sub-nanometric ones lose this magnetic behavior.
Seed layer technique for high quality epitaxial manganite films
2016
We introduce an innovative approach to the simultaneous control of growth mode and magnetotransport properties of manganite thin films, based on an easy-to-implement film/substrate interface engineering. The deposition of a manganite seed layer and the optimization of the substrate temperature allows a persistent bi-dimensional epitaxy and robust ferromagnetic properties at the same time. Structural measurements confirm that in such interface-engineered films, the optimal properties are related to improved epitaxy. A new growth scenario is envisaged, compatible with a shift from heteroepitaxy towards pseudo-homoepitaxy. Relevant growth parameters such as formation energy, roughening tempera…
High-Z Materials for X-ray Detection: Material Properties and Characterization Techniques
2023
This book will provide readers with a good overview of some of most recent advances in the field of High-Z materials. There will be a good mixture of general chapters in both technology and applications in opto-electronics, X-ray detection and emerging optoelectronics applications. The book will have an in-depth review of the research topics from world-leading specialists in the field.
A novel TiO2-assisted magnetic nanoparticle separator for treatment and inactivation of bacterial contaminants in aquatic systems
2014
Ferromagnetic nanoparticles (Fe-nanoparticles) have been functionalized with recombinant poly- Glu [glutamic acid]-tagged silicatein, a biomineral-synthesizing enzyme from siliceous sponges that forms the inorganic silica skeleton of those animals. The biocatalytic activity of silicatein was used to form a titania (TiO2) shell around the iron nanoparticle core, using the water-soluble non- natural substrate titanium bis(ammonium lactato)-dihydroxide (TiBALDH). Thereby the diameter of the nanoparticles increases from 7 nm to ≈22 nm. This procedure also allows the layer-by-layer fabrication of titania/silica- Fe-nanoparticles. SEM/EDX analysis confirmed the presence of the Ti and Si signals i…
Transport de la variabilité dans les matériaux composites = Uncertainties propagation in composite materials
2009
National audience; Dans ce travail, une méthodologie de transport d'incertitudes à travers les différentes échelles d'observation des matériaux composites : (i) micro (fibres et matrice), (ii) méso (pli), (iii) macro (matériau stratifié) est proposée. L'objectif est d'intégrer à l'échelle macro (celle du calcul de structure) l'effet des incertitudes venant de l'échelle micro et celle des incertitudes introduites à chacune des échelles méso et macro. La démarche proposée s'appuie sur l'élaboration dès l'échelle micro de distributions statistiques bâties sur l'analyse morphologique et obtenues grâce à la génération de matériaux virtuels.