Highly selective epoxidation of styrene using a transition metal–aluminium(iii) complex containing the [MeAl(2-py)3]−anion (2-py = 2-pyridyl)

2005 ◽  
pp. 198-200 ◽  
Author(s):  
Carmen Soria Alvarez ◽  
Felipe García ◽  
Simon M. Humphrey ◽  
Alexander D. Hopkins ◽  
Richard A. Kowenicki ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Aluminium

X-Ray Spectra and Electronic Structure of Some CsCl-Type Transition Metal-Aluminium Alloys

1979 ◽  
Vol 93 (2) ◽  
pp. 713-720 ◽  
Author(s):  
W. Blau ◽  
J. Weisbach ◽  
G. Merz ◽  
K. Kleinstück
Keyword(s):  
Electronic Structure ◽  
Transition Metal ◽  
Aluminium Alloys ◽  
X Ray ◽  
Type Transition ◽  
Cscl Type ◽  
Metal Aluminium

Selective wet air oxidation of diluted aqueous ammonia solutions over co-precipitated transition metal-aluminium catalysts

2002 ◽  
Vol 28 (5) ◽  
pp. 471-477 ◽  
Author(s):  
Sutasinee Kaewpuang-Ngam ◽  
Koji Inazu ◽  
Ken-Ichi Aika
Keyword(s):  
Transition Metal ◽  
Aqueous Ammonia ◽  
Air Oxidation ◽  
Wet Air Oxidation ◽  
Metal Aluminium

scholarly journals Modelling the energy gap in transition metal/aluminium bilayers

2001 ◽  
Vol 350 (3-4) ◽  
pp. 227-236 ◽  
Author(s):  
G Brammertz ◽  
A Golubov ◽  
A Peacock ◽  
P Verhoeve ◽  
D.J Goldie ◽  
...  
Keyword(s):  
Transition Metal ◽  
Energy Gap ◽  
Metal Aluminium

scholarly journals Microstructure and composition of rare earth-transition metal-aluminium-magnesium alloys

2008 ◽  
Vol 11 (1) ◽  
pp. 17-21 ◽  
Author(s):  
Lia Maria Carlotti Zarpelon ◽  
Eguiberto Galego ◽  
Hidetoshi Takiishi ◽  
Rubens Nunes Faria
Keyword(s):  
Rare Earth ◽  
Transition Metal ◽  
Magnesium Alloys ◽  
Metal Aluminium

Glancing angle XAFS and X-ray reflectivity studies of transition-metal/aluminium interfaces

1990 ◽  
Vol 89 ◽  
pp. 21 ◽  
Author(s):  
Steve M. Heald ◽  
Enrique V. Barrera ◽  
Huaiyu Chen
Keyword(s):  
Transition Metal ◽  
X Ray ◽  
Glancing Angle ◽  
Metal Aluminium

HREM Study of electron-induced surface radiation damage in ReO3

1991 ◽  
Vol 49 ◽  
pp. 636-637
Author(s):  
R. Ai ◽  
H.-J. Fan ◽  
L. D. Marks
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Metal Oxides ◽  
Electron Irradiation ◽  
Transition Metal Oxides ◽  
Carbon Film ◽  
Transition Metal Ions ◽  
Surface Radiation ◽  
Valence Transition ◽  
Electron Microscopes

It has been known for a long time that electron irradiation induces damage in maximal valence transition metal oxides such as TiO2, V2O5, and WO3, of which transition metal ions have an empty d-shell. This type of damage is excited by electronic transition and can be explained by the Knoteck-Feibelman mechanism (K-F mechanism). Although the K-F mechanism predicts that no damage should occur in transition metal oxides of which the transition metal ions have a partially filled d-shell, namely submaximal valence transition metal oxides, our recent study on ReO3 shows that submaximal valence transition metal oxides undergo damage during electron irradiation.ReO3 has a nearly cubic structure and contains a single unit in its cell: a = 3.73 Å, and α = 89°34'. TEM specimens were prepared by depositing dry powders onto a holey carbon film supported on a copper grid. Specimens were examined in Hitachi H-9000 and UHV H-9000 electron microscopes both operated at 300 keV accelerating voltage. The electron beam flux was maintained at about 10 A/cm2 during the observation.

Alignment of small He-Bubbles during in situ deformation of Al-foils

1978 ◽  
Vol 36 (1) ◽  
pp. 396-397
Author(s):  
E. Ruedl ◽  
P. Schiller
Keyword(s):  
Fusion Reactor ◽  
Matrix Material ◽  
Fusion Reactors ◽  
First Wall ◽  
Potential Matrix ◽  
In Situ Deformation ◽  
Α Particles ◽  
Metal Aluminium

The low Z metal aluminium is a potential matrix material for the first wall in fusion reactors. A drawback in the application of A1 is the rel= atively high amount of He produced in it under fusion reactor conditions. Knowledge about the behaviour of He during irradiation and deformation in Al, especially near the surface, is therefore important.Using the TEM we have studied Al disks of 3 mm diameter and 0.2 mm thickness, which were perforated at the centre by double jet polishing. These disks were bombarded at∽200°C to various doses with α-particles, impinging at any angle and energy up to 1.5 MeV at both surfaces. The details of the irradiations are described in Ref.1. Subsequent observation indicated that in such specimens uniformly distributed He-bubbles are formed near the surface in a layer several μm thick (Fig.1).After bombardment the disks were deformed at 20°C during observation by means of a tensile device in a Philips EM 300 microscope.

Problems with oxygen analysis in the system MgO-Al2O3-SiO2 with the electron microprobe

1992 ◽  
Vol 50 (2) ◽  
pp. 1624-1625
Author(s):  
Michel Fialin ◽  
Guy Rémond
Keyword(s):  
Transition Metal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Electrostatic Charge ◽  
Carbon Layer ◽  
Sample Holder ◽  
Rock Matrix ◽  
Electrical Discharges ◽  
Thin Carbon ◽  
Beam Instabilities

Oxygen-bearing minerals are generally strong insulators (e.g. silicates), or if not (e.g. transition metal oxides), they are included within a rock matrix which electrically isolates them from the sample holder contacts. In this respect, a thin carbon layer (150 Å in our laboratory) is evaporated on the sections in order to restore the conductivity. For silicates, overestimated oxygen concentrations are usually noted when transition metal oxides are used as standards. These trends corroborate the results of Bastin and Heijligers on MgO, Al2O3 and SiO2. According to our experiments, these errors are independent of the accelerating voltage used (fig.l).Owing to the low density of preexisting defects within the Al2O3 single-crystal, no significant charge buildup occurs under irradiation at low accelerating voltage (< 10keV). As a consequence, neither beam instabilities, due to electrical discharges within the excited volume, nor losses of energy for beam electrons before striking the sample, due to the presence of the electrostatic charge-induced potential, are noted : measurements from both coated and uncoated samples give comparable results which demonstrates that the carbon coating is not the cause of the observed errors.

Electron energy loss near edge structures of intermetallic alloys and grain boundaries in NiAl

1996 ◽  
Vol 54 ◽  
pp. 522-523
Author(s):  
G.A. Botton ◽  
C.J. Humphreys
Keyword(s):  
High Temperature ◽  
Transition Metal ◽  
Energy Loss ◽  
Grain Boundaries ◽  
Industrial Applications ◽  
Edge Structure ◽  
Structural Applications ◽  
Yield Behaviour ◽  
Late Transition ◽  
Metal Aluminides

Transition metal aluminides are of great potential interest for high temperature structural applications. Although these materials exhibit good mechanical properties at high temperature, their use in industrial applications is often limited by their intrinsic room temperature brittleness. Whilst this particular yield behaviour is directly related to the defect structure, the properties of the defects (in particular the mobility of dislocations and the slip system on which these dislocations move) are ultimately determined by the electronic structure and bonding in these materials. The lack of ductility has been attributed, at least in part, to the mixed bonding character (metallic and covalent) as inferred from ab-initio calculations. In this work, we analyse energy loss spectra and discuss the features of the near edge structure in terms of the relevant electronic states in order to compare the predictions on bonding directly with spectroscopic experiments. In this process, we compare spectra of late transition metal (TM) to early TM aluminides (FeAl and TiAl) to assess whether differences in bonding can also be detected. This information is then discussed in terms of bonding changes at grain boundaries in NiAl.

A new lithium diffusion model in layered oxides based on asymmetric but reversible transition metal migration

2020 ◽  
Vol 13 (4) ◽  
pp. 1269-1278 ◽  
Author(s):  
Kyojin Ku ◽  
Byunghoon Kim ◽  
Sung-Kyun Jung ◽  
Yue Gong ◽  
Donggun Eum ◽  
...  
Keyword(s):  
Transition Metal ◽  
Diffusion Model ◽  
Layered Oxides ◽  
Layered Oxide ◽  
Reversible Transition ◽  
Lithium Diffusion ◽  
Metal Migration

We propose a new lithium diffusion model involving coupled lithium and transition metal migration, peculiarly occurring in a lithium-rich layered oxide.

Sign in / Sign up

Export Citation Format

Share Document