scholarly journals Core-level spectra and binding energies of transition metal nitrides by non-destructive x-ray photoelectron spectroscopy through capping layers

2017 ◽  
Vol 396 ◽  
pp. 347-358 ◽  
Author(s):  
G. Greczynski ◽  
D. Primetzhofer ◽  
J. Lu ◽  
L. Hultman
2018 ◽  
Vol 20 (13) ◽  
pp. 8403-8410 ◽  
Author(s):  
Francesc Viñes ◽  
Carmen Sousa ◽  
Francesc Illas

Core level binding energies, measured by X-ray photoelectron spectroscopy providing unique information regarding the chemical environment of atoms in a system, can be estimated by a diversity of state-of-the-art accurate methods here detailed.


1987 ◽  
Vol 41 (6) ◽  
pp. 994-1000 ◽  
Author(s):  
V. Y. Young ◽  
F. C. Chang ◽  
K. L. Cheng

X-ray photoelectron spectroscopy has been used to determine the oxidation state of nickel in the oxidized nickel (II) dimethylglyoxime complex. Core level binding energies for the Ni(2p), N(1s), and O(1s) levels; the presence or absence of shake-up satellites on the Ni(2p) levels; and the analysis of intensity data are consistent only with an assignment of +3. Structures consistent with the data are proposed for both the solid-and the solution-phase complexes.


1986 ◽  
Vol 82 ◽  
Author(s):  
H. E. Rhodes ◽  
G. Apai

ABSTRACTWe have studied the atomic states of arsenic (As) and phosphorus (P) in SiO2 using X-ray photoelectron spectroscopy (XPS). Silicon dioxide implanted with As or P shows multiple XPS core level peaks corresponding to the impurity atoms located in two distinct atomic sites. The binding energies of the two arsenic 3d core levels occur at 45.8 and 42.3 eV and the two phosphorus 2p core levels occur at 134.7 and 130.3 eV. When the implanted oxides are annealed in an oxygen ambient between 900°C and 950°C, only the highbinding- energy peaks of P and As are observed. This identifies the highbinding- energy core level peaks as being associated with the impurity (P or As) on silicon sites. Annealing in nitrogen at 950° C results in an increase in the low-binding-energy signal. The low-binding-energy peaks are associated with the impurity (P or As) bonded to silicon neighbors. The relative amounts of dopants in silicon and oxygen sites depend on ambient purity and processing details. Reference to previous work shows that the presence of As or P on silicon sites in SiO2 corresponds to a fast diffusing state whereas As or P on oxygen sites corresponds to a slow diffusing state [1].


2007 ◽  
Vol 29-30 ◽  
pp. 195-198
Author(s):  
S. Mondal ◽  
A.K. Banthia

Nitrides remain a relatively unexplored class of materials primarily due to the difficulties associated with their synthesis and characterization. Several synthetic routes, including high temperature reactions, microwave assisted synthesis, and the use of plasmas, to prepare binary and ternary nitrides have been explored. Transition metal nitrides form a class of materials with unique physical properties, which give them varied applications, as high temperature ceramics, magnetic materials, superconductors or catalysts. They are commonly prepared by high temperature conventional processes, but alternative synthetic approaches have also been explored, more recently, which utilize moderate temperature condition. Transition metal nitrides particularly, molybdenum nitride, niobium nitride, and tungsten nitride have important applications as catalyst in hydrodenitridation reactions. These nitrides have been traditionally synthesized using high temperature nitridation treatments of the oxides. The nitridation temperatures are very high (> 800- 1000 oC). The aim of our work is to synthesize molybdenum nitride by a simple, low-temperature route. The method involves pyrolysis of a polymeric precursor, which was prepared from the condensation reaction between triethanolamine and molybdic acid. The melting point of the product is 180oC. The polymeric precursor and its pyrolyzed products are characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). X-ray diffraction shows that molybdenum nitride (MoN) obtained from this method has hexagonal crystal structure. MoN is obtained by this method at very low temperature (~ 400 oC).


1995 ◽  
Vol 410 ◽  
Author(s):  
Joel D. Houmes ◽  
David S. Bem ◽  
Hans-Conrad Zur Loye

ABSTRACTSeveral novel transition metal nitrides and oxynitrides were synthesized via ammonolysis of solid state oxide precursors at temperatures ranging from 700°C-900°C and reaction times ranging from 12 hours to 4 days. The products were characterized by powder X-ray diffraction and their structures were determined by powder X-ray Rietveld refinement. The relationships between the structures of these nitrides and oxynitrides, and their similarity to the structures of the transition metal dichalcogenides, is discussed.


Author(s):  
S.M. Widstrand ◽  
K.O. Magnusson ◽  
L.S.O. Johansson ◽  
E. Moons ◽  
M. Gurnett ◽  
...  

We report on a high-resolution x-ray photoelectron spectroscopy (HRXPS) study using synchrotron radiation, for the identification of the core level binding energies of Ga 3d and N 1s, from a stoichiometric Ga-polar GaN(0001)-1×1 sample.Three surface shifted components were found on the stoichiometric surface for the Ga 3d feature. The first surface shifted component has a higher binding energy of 0.85 eV, and is interpreted as surface Ga with one of the N bonds replaced by an empty dangling bond. This structure is belonging to the stoichiometric clean and ordered Ga-polar GaN(0001)-1×1 surface. The second, with a binding energy relative the bulk of −0.76 eV, is interpreted as Ga with one of the bonds to a Ga atom, which indicates a slight excess of Ga on the surface. The third surface shifted component is shifted by 2.01 eV and is related to gallium oxide in different configurations.The N 1s feature is complex with five surface shifted components relative the bulk were found. Two components with binding energy shifts of −0.54 eV and 0.47 eV are interpreted as surface shifted core levels from the stoichiometric, clean Ga-polar GaN(0001)-1×1 surface.We also analysed the Ga 3d spectrum after deposition of 1.5 ML of Ga on a stoichiometric surface. The surface shift for the Ga 3d5/2 component from the Ga overlayer is −1.74 eV relative the bulk GaN.The C 1s and O 1s core levels from remaining surface contamination have also been line shaped analysed and show complex structures.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yanfei Zhao ◽  
Hongwei Gao ◽  
Rong Huang ◽  
Zengli Huang ◽  
Fangsen Li ◽  
...  

AbstractWe present a systematic study of surface band bending in Ga-polar n-GaN with different Si doping concentrations by angular dependent X-ray photoelectron spectroscopy (ADXPS). The binding energies of Ga 3d and N 1 s core levels in n-GaN films increase with increasing the emission angle, i. e., the probing depth, suggesting an upward surface band bending. By fitting the Ga 3d core level spectra at different emission angles and considering the integrated effect of electrostatic potential, the core level energy at the topmost surface layer is well corrected, therefore, the surface band bending is precisely evaluated. For moderately doped GaN, the electrostatic potential can be reflected by the simply linear potential approximation. However, for highly doped GaN samples, in which the photoelectron depth is comparable to the width of the space charge region, quadratic depletion approximation was used for the electrostatic potential to better understand the surface band bending effect. Our work improves the knowledge of surface band bending determination by ADXPS and also paves the way for studying the band bending effect in the interface of GaN based heterostructures.


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