Measuring concentration depth profiles at liquid surfaces: Comparing angle resolved X-ray photoelectron spectroscopy and neutral impact collision scattering spectroscopy

2011 ◽  
Vol 605 (9-10) ◽  
pp. 889-897 ◽  
Author(s):  
Chuangye Wang ◽  
Gunther G. Andersson
Keyword(s):  
Photoelectron Spectroscopy ◽  
X Ray ◽  
Depth Profiles ◽  
Concentration Depth Profiles ◽  
Liquid Surfaces

scholarly journals Montecarlo Simulation and HAXPES Analysis of Organosilane Segregation in Titania Xerogel Films; Towards a Generic Surface Chemofunctionalization Process

Surfaces ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 352-365
Author(s):  
Javier Mateo Moreno ◽  
Rodrigo Calvo Membibre ◽  
Sergio Pinilla Yanguas ◽  
Juan Rubio Zuazo ◽  
Miguel Manso Siván
Keyword(s):  
Photoelectron Spectroscopy ◽  
Surface Segregation ◽  
Titanium Isopropoxide ◽  
Condensation Process ◽  
X Ray ◽  
Depth Profiles ◽  
Partial Charges ◽  
Xerogel Films ◽  
Non Destructive

The formation of xerogels implies a sequence of hydrolysis and condensation reactions, which are intricate to analyze in heteromolecular sols. We analyze by probabilistic Montecarlo methods the development of hybrid organosilane–titania xerogels and illustrate how partial charges of the reacting molecules can help estimating relative probabilities for the condensation of the molecules. Since the condensation rate of Ti alkoxides is much higher than the corresponding rate of Si alkoxides (especially if bearing a non-hydrolizable group), by imposing a fast condensation process in agreement with low pH kinetics, the process leads to a surface segregation of the organosilane. The simulation results are compared with results of characterization of thin condensates of two different organosilanes within a titanium–isopropoxide matrix. Non-destructive in-depth profiles were obtained by hard x-ray photoelectron spectroscopy, which can resolve through estimation of Si and specific moieties of the organosilane molecules the progress of the condensation. These results are relevant for the generalization of chemo-functionalization processes by kinetic demixing of organosilanes, which have myriad applications in biomedicine and biotechnology.

Interdiffusion in Exchange Biased NiFe/IrMn/CoFe Electrode in Magnetic Tunnel Junctions

2001 ◽  
Vol 690 ◽  
Author(s):  
Jay H. Lee ◽  
Hee D. Jeong ◽  
Il C. Rho ◽  
Chong S. Yoon ◽  
Chang K. Kim
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electron Spectroscopy ◽  
Tunnel Junctions ◽  
Magnetic Tunnel Junction ◽  
Magnetic Film ◽  
Tunnel Barrier ◽  
Plasma Oxidation ◽  
X Ray ◽  
Depth Profiles ◽  
Mn Diffusion

ABSTRACTExtent of Mn diffusion to the plasma-oxidized AlOx tunnel barrier of magnetic tunnel junction was examined using Auger Electron Spectroscopy (AES) and X-Ray Photoelectron Spectroscopy (XPS). A magnetic film stack consisting of Ta/AlOx/CoFe/IrMn/NiFe/Ta was deposited with the AlOx layer treated under different plasma oxidation durations. AES depth profiles showed that Mn diffusion to the AlOx/CoFe interface increased with increasing oxidation after annealing at 300°C. XPS analysis indicated that Mn found at the CoFe/AlOx interface in the over-oxidized electrode was in the form of MnO2. Our research suggests that Mn diffusion was accelerated by preferential oxidation of Mn at the CoFe/AlOx interface.

Damage Removal and Activation in Rapid-Thermally-Annealed Silicon Implanted Semi-Insulating GaAs

1988 ◽  
Vol 126 ◽  
Author(s):  
J. L. Tandon ◽  
J. H. Madok ◽  
I. S. Leybovich ◽  
G. Bai
Keyword(s):  
Electron Concentration ◽  
Lattice Strain ◽  
Extended Defects ◽  
Strain Measurements ◽  
X Ray ◽  
Depth Profiles ◽  
Annealing Temperatures ◽  
Implantation Damage ◽  
Long Tails ◽  
Concentration Depth Profiles

ABSTRACTIn the Rapid-Thermal-Annealing of Si-implanted undoped semi-insulating GaAs three regimes are broadly identified. At ˜ 600°C, ion implantation damage is largely removed, as indicated by lattice-strain measurements performed by X-ray rocking curves. Between ˜ 600 – 900°C, “extended defects”, which presumably account for the long tails in the electron concentration depth profiles, are annealed. Higher annealing temperatures in this range result in profiles with successively shorter tails. Finally, beyond ˜ 900°C, “acceptor levels” in the material are revealed, which become effective in compensating the Si activation.

Angle-Resolved X-Ray Depth Profiling: Interpretation of Angleresolved Profiles Using a Monte Carlo Approach

1999 ◽  
Vol 5 (S2) ◽  
pp. 582-583
Author(s):  
D.K. Wilkinson ◽  
M. Prutton ◽  
D.A. Loveday
Keyword(s):  
Monte Carlo ◽  
Electron Scattering ◽  
Photoelectron Spectroscopy ◽  
Depth Profiling ◽  
Incident Beam ◽  
Angle Of Incidence ◽  
X Rays ◽  
X Ray ◽  
Interaction Volume ◽  
Depth Profiles

A technique has been developed for the interpretation of composition depth profiles from angleresolved x-ray data using a Monte Carlo electron scattering simulation. Conventional methods for the interpretation of angle-resolved depth profiles used in the fields of x-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) assume that the outgoing signal is exponentially attenuated along its path. This assumption if not valid for angle-resolved x-ray techniques, as the x-ray signal is dependent on both the paths of the incident electrons and the path of the emitted x-rays. In this case, while the latter can be treated using an exponential attenuation, the path of the incident beam is more complex and corresponds to the well known “pear-shaped” interaction volume. In order to reliably interpret angle-resolved depth profiles in which the angle of the incident beam is varied, it is necessary to be able to obtain the distribution of x-ray emission within the sample for any angle of incidence.

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