Theoretical simulation of core-level photoemission in transition-metal oxides

2005 ◽  
Vol 72 (12) ◽  
Author(s):  
C. A. Rozzi ◽  
F. Manghi ◽  
C. Calandra
Keyword(s):  
Transition Metal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Core Level ◽  
Theoretical Simulation

scholarly journals Influence of shallow core-level hybridization on the electronic structure of post-transition-metal oxides studied using soft X-ray emission and absorption

2003 ◽  
Vol 68 (16) ◽  
Author(s):  
Cormac McGuinness ◽  
Cristian B. Stagarescu ◽  
Philip J. Ryan ◽  
James E. Downes ◽  
Dongfeng Fu ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Transition Metal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Core Level ◽  
X Ray

SYSTEMATICS IN THE O 1s CORE-LEVEL SPECTRA IN TRANSITION METAL OXIDES, LaMO3 (M = V, Cr, Mn, Fe, Co AND Ni)

1990 ◽  
Vol 04 (04) ◽  
pp. 277-282 ◽  
Author(s):  
G. RANGA RAO ◽  
D. D. SARMA
Keyword(s):  
Transition Metal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Core Level ◽  
Broad Peak ◽  
Main Peak ◽  
Considerable Part ◽  
Impurity Contamination ◽  
Hole Configuration

The O 1s core level spectra of transition metal oxides, LaMO 3 (M = V, Cr, Mn, Fe, Co and Ni) show three features. The main peak always appears between 528 and 530 eV and is attributed to the well-screened oxygen 1s1 2p0 hole configuration in every case. The poorly-screened feature (1s1 2p1 hole configuration) is found as a broad peak centred approximately 13 eV above the main peak. Another feature is at about 531 eV; the intensity of this peak is found to increase systematically across the series and its intensity cannot be explained in terms of carbonate impurity contamination. It is suggested that a considerable part of this 531 eV feature has an intrinsic origin.

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.

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.

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