Gas-phase studies of alkene oxidation by transition-metal oxides. Ion-beam studies of CrO+

1986 ◽  
Vol 108 (19) ◽  
pp. 5663-5668 ◽  
Author(s):  
H. Kang ◽  
J. L. Beauchamp
Keyword(s):  
Transition Metal ◽  
Metal Oxides ◽  
Gas Phase ◽  
Transition Metal Oxides ◽  
Ion Beam ◽  
Alkene Oxidation

Onset Conditions for Gas Phase Reaction and Nucleation in the CVD of Transition Metal Oxides

1991 ◽  
Vol 250 ◽  
Author(s):  
J. Collins ◽  
D. E. Rosner ◽  
J. Castillo
Keyword(s):  
Transition Metal ◽  
Metal Oxides ◽  
Gas Phase ◽  
Transition Metal Oxides ◽  
Film Theory ◽  
Operating Conditions ◽  
Particle Nucleation ◽  
Phase Reaction ◽  
Homogeneous Reaction ◽  
Gas Phase Reaction

AbstractA combined experimental/theoretical study is presented of the onset conditions for gas phase reaction and particle nucleation in hot substrate/cold gas CVD of transition metal oxides. Homogeneous reaction onset conditions are predicted using a simple high activation energy reacting gas film theory. Experimental tests of the basic theory are underway using an axisymmetric impinging jet CVD reactor. No “vapor phase ignition” has yet been observed in the TiCl4/O2 system under accessible operating conditions (below substrate temperature Tw=1700 K) and further experiments are planned using more reactive feed materials. The goal of this research is to provide CVD reactor design and operation guidelines for achieving acceptable deposit microstructures at the maximum deposition rate while simultaneously avoiding homogeneous reaction/nucleation and diffusional limitations.

Interaction of perovskite-like compounds based on transition-metal oxides with gas phase at T = 200–400°C

2014 ◽  
Vol 115 (6) ◽  
pp. 547-556 ◽  
Author(s):  
N. A. Zyuzeva ◽  
I. B. Bobylev ◽  
S. V. Naumov ◽  
E. P. Romanov
Keyword(s):  
Transition Metal ◽  
Metal Oxides ◽  
Gas Phase ◽  
Transition Metal Oxides

Electronic Structures and Gas-Phase Reactivities of Cationic Late-Transition-Metal Oxides

1994 ◽  
Vol 116 (23) ◽  
pp. 10734-10741 ◽  
Author(s):  
Andreas Fiedler ◽  
Detlef Schroeder ◽  
Sason Shaik ◽  
Helmut Schwarz
Keyword(s):  
Transition Metal ◽  
Metal Oxides ◽  
Gas Phase ◽  
Transition Metal Oxides ◽  
Electronic Structures ◽  
Late Transition Metal ◽  
Late Transition

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.

Sign in / Sign up

Export Citation Format

Share Document