Measurement of Thin Oxide Surface Film Thicknesses and Atomic Densities by the Analysis of Positive Ion Excited Soft X-Ray Spectral

AbstractCharacteristic soft x-ray emission lines created as a result of low energy (10-100keV) positive ion excitation of a target material has been applied to the study of thin films of oxygen that form naturally on metal surfaces. The specific metals investigated were aluminum and nickel aa well as a number of their corresponding alloys.Low energy positive ions are well suited as projectiles for the study of thin films in that they have low penetrating powers, yet produce high x-ray yields for K-, L-, and M-shell elemental x-ray lines. Perhaps the most important feature is the fact that no background bremsstrahlung continuum x-radiation is generated in the slowing processes of the ions. Exploiting the advantages of these facts, a special high sensitivity detection technique has been developed for the soft x-ray analysis of the constituents that make up a particular thin surface film.The physical basis for thickness and atomic density measurements of thin surface films by positive ion excitation are discussed. Calibration data are presented for thin films of known thickness and composition establishing the sensitivity of the method for the measurement of the elemental atomic densities of thin films down to a few monolayers or approximately 10 Å in thickness. Finally, the results of the analysis of oxide surface films of aluminum, nickel and some of their alloys are presented and discussed.The objective of this continuing program is to gain an understanding of the mechanisms and principles governing the formation of oxide surface films on metals with the basic goal of producing new alloying techniques for metal passification in a saline environment.

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Measurement of Thin Oxide Surface Film Thicknesses and Atomic Densities by the Analysis of Positive Ion Excited Soft X-Ray Spectra

Advances in X-Ray Analysis ◽

10.1007/978-1-4684-7535-7_30 ◽

1969 ◽

pp. 457-479

Author(s):

W. P. Saylor ◽

C. L. Marks

Keyword(s):

Surface Film ◽

Oxide Surface ◽

X Ray ◽

Thin Oxide ◽

Positive Ion

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The sensitivity of atomic analysis by X-rays

Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character ◽

10.1098/rspa.1932.0058 ◽

1932 ◽

Vol 135 (828) ◽

pp. 637-656 ◽

Cited By ~ 3

Keyword(s):

Atomic Number ◽

Target Material ◽

High Sensitivity ◽

Major Constituent ◽

X Rays ◽

Depth Of Penetration ◽

X Ray ◽

Constituent Element ◽

The Difference ◽

Atomic Analysis

In a previous paper it was shown that 0·0007 per cent, of 29 Cu and 0·0003 per cent, of 26 Fe could be detected in 30 Zn by atomic analysis by X-ray spectroscopy. This sensitivity is greater than that which was claimed by Noddack, Tacke, and Berg, who set the limit at about 0·1 per cent, for non-metals, and by Hevesy, who stated it to be about 0·01 per cent, for an element present in an alloy. It was later suggested by Hevesy that the high value of the sensitivity which we found might result from the fact that some of the alloys we had used were composed of elements of almost equal atomic number, and that the sensitivity would be smaller for a constituent of low atomic number mixed with a major constituent of high atomic number. To elucidate these disagreements we have made further observations of the sensitivity with elements of different atomic number and have investigated the conditions which can influence the sensitivity. The Factors Determining Sensitivity . The detection of one element in a mixture of elements depends upon the identification of its K or L lines in the general spectrum emitted by the mixture under examination. The intensity with which these lines are excited in the target (“excited intensity”) is proportional to the number of atoms of the constituent element excited, i. e ., to its concentration and to the volume of the target in which the cathode ray energy is absorbed. The depth of penetration of the cathode rays is determined by the density of the target material and by their velocity ( i. e ., by the voltage applied to the X-ray tube). Schonland has shown that the range of homogeneous cathode rays in different elements, expressed as a mass per unit area, is approximately constant and is independent of the atomic number of the absorbing element. When their velocity is increased, the cathode rays will penetrate to a greater depth, and therefore a greater number of atoms of all constituents will be ionised. This will increase the “excited intensity” of the lines due to the particular constituent sought equally with those lines of the other elements present. The intensity of a line further depends upon the difference between the voltage applied to the X-ray tube and that necessary to excite the series. For these reasons, a high applied voltage is required for a high sensitivity.

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Effects of Irradiation by Low Energy Nitrogen Ions on Carbon Nitride Thin Films

MRS Proceedings ◽

10.1557/proc-750-y5.33 ◽

2002 ◽

Vol 750 ◽

Author(s):

Yuka Nasu ◽

Masami Aono ◽

Shinichiro Aizawa ◽

Nobuaki Kitazawa ◽

Yoshihisa Watanabe

Keyword(s):

Thin Films ◽

Nitrogen Content ◽

Vapor Deposition ◽

Photoelectron Spectroscopy ◽

Carbon Nitride ◽

Chemical Vapor ◽

Low Energy ◽

Carbon Filament ◽

X Ray ◽

Nitrogen Ions

ABSTRACTCarbon nitride (CNx) thin films have been prepared by hot carbon filament chemical vapor deposition, and the nitrogen content in the films is approximately 0.05. The CNx films have been irradiated by 0.1 keV nitrogen ions to increase the nitrogen content after deposition. The nitrogen content in the CNx films was obtained with X-ray photoelectron spectroscopy. Scanning electron microscopy was employed to study microstructures of the films. The experimental results show that nitrogen ions are chemically combined with the CNx films and as a result the nitrogen content increases up to approximately 0.30. Furthermore, it is found that nitrogen ions change the film microstructures and sputter the surfaces of CNx films.

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Sensing of Ethanol with Nanosize FeZnO Thin Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.47-50.1117 ◽

2008 ◽

Vol 47-50 ◽

pp. 1117-1120

Author(s):

G.H. Kuo ◽

H. Paul Wang ◽

H.H. Hsu ◽

Chih Ju G. Jou ◽

Y.M. Chiu ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

High Sensitivity ◽

Zno Thin Films ◽

X Ray ◽

Doped Zno ◽

Low Sensitivity ◽

X Ray Absorption ◽

Exafs Spectra

In the present work, sensing of ethanol on the ZnO thin films doped with Fe (5-50%) have been investigated. Nature of the sensing species in the nanosize Fe-doped ZnO (FeZnO) thin films has also been studied by in situ extended X-ray absorption fine structure (EXAFS) spectroscopy. By XRD, it is found that ZnO and ZnFe2O4 are the main compounds in the ZnO-Fe thin films. The thin film containing 5% of Fe has a high sensitivity (Rair/Rethanol>80) when sensing of ethanol at 300 K. On the contrary, the thin films with Fe fractions of 20-50% have a very low sensitivity to ethanol (Rair/Rethanol<15). In the presence of ethanol, the EXAFS spectra show that the bond distances of Zn-O and Fe-O in the thin films are 1.90 and 1.98 Å, respectively and restored to 1.91 and 1.97 Å in the absence of ethanol.

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DEPOSITION OF TiAlV THIN FILMS BY PULSED LASER AND DC MAGNETRON SPUTTERING: STRUCTURAL, COMPOSITIONAL AND ELECTROCHEMICAL CORROSION STUDY

Surface Review and Letters ◽

10.1142/s0218625x19501889 ◽

2019 ◽

Vol 27 (08) ◽

pp. 1950188

Author(s):

A. ALKHAWWAM ◽

B. ABDALLAH ◽

A. K. JAZMATI ◽

M. TOOTANJI ◽

F. LAHLAH

Keyword(s):

Thin Films ◽

Magnetron Sputtering ◽

Corrosion Test ◽

Pulsed Laser ◽

Electrochemical Corrosion ◽

Target Material ◽

X Ray Diffraction ◽

Dc Magnetron Sputtering ◽

Film Properties ◽

X Ray

In this work, TiAlV thin films have been prepared on two different types of substrates: silicon and stainless steel (SS304) by two deposition methods: Pulsed Laser Deposition (PLD) and DC magnetron sputtering. Different techniques have been employed in order to characterize film properties such as: Scanning Electron Microscopy (SEM) equipped with Energy Dispersive X-ray (EDX), X-ray diffraction (XRD), microhardness and corrosion test. EDX analysis showed that the deposited films are slightly different from that of the target material Ti6Al4V alloy. The measured microhardness values are about 11.7[Formula: see text]GPa and 4.7[Formula: see text]GPa for films prepared by PLD and DC magnetron sputtering, respectively. Corrosion test indicated that the corrosion resistance of the two TiAlV films deposited on SS304 substrates in (0.9% NaCl) physiological normal saline medium was significantly improved compared with the SS304 substrates. These attractive results could permit applications of our films in the medical implants fabrication.

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Soft X-Ray Valance State Effects in Conductors

Advances in X-ray Analysis ◽

10.1154/s0376030800011344 ◽

1969 ◽

Vol 13 ◽

pp. 136-157 ◽

Cited By ~ 4

Author(s):

J. E. Holliday

Keyword(s):

Thin Films ◽

Transition Metal ◽

Intensity Ratio ◽

Low Energy ◽

Ionic Character ◽

Electrode Geometry ◽

Band Shape ◽

X Ray ◽

Electronegativity Difference ◽

Band Spectra

Investigation of the NiLIII band at various excitation voltages and the use of Ni and Ti thin films in the path of the NiLII,III and TiLII,III radiation, has shown that with proper electrode geometry and using target voltages of about 4 kv the effect of self absorption on emission edge shift and band shape is negligible for these elements. However, the LII/LIII intensity ratio of titanium is strongly effected by self absorption, but it is not effected for nickel and iron by self absorption.A survey of several investigators’ soft x-ray band spectra from alloys and conducting compounds showed that the observed band changes were related to the electronegativity difference of the combining elements or the ionic character of the band. Peaks appearing on the low energy side of transition metal bands when combined with 2nd period elements appear to be a cross transition between the 2s or 2p band of the non-metal and inner level of the metal.

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Effect of low-energy N2+ ion beam bombardment on silicate glass thin films studied by x-ray photoelectron spectroscopy

Journal of Applied Physics ◽

10.1063/1.1450027 ◽

2002 ◽

Vol 91 (6) ◽

pp. 3626-3631

Author(s):

M. Garcı́a ◽

I. Montero ◽

J. M. Ripalda ◽

L. Galán

Keyword(s):

Thin Films ◽

Silicate Glass ◽

Photoelectron Spectroscopy ◽

Ion Beam ◽

Low Energy ◽

X Ray

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The initial stages of lead oxidation in pH 9 to 14 aqueous solutions

Canadian Journal of Chemistry ◽

10.1139/v89-165 ◽

1989 ◽

Vol 67 (6) ◽

pp. 1098-1104 ◽

Cited By ~ 11

Author(s):

V. I. Birss ◽

W. Waudo

Keyword(s):

Cyclic Voltammetry ◽

Surface Film ◽

Alkaline Solutions ◽

Oxide Surface ◽

Surface Films ◽

Ion Content ◽

Initial Product ◽

Carbonate Solutions ◽

Lead Hydroxide ◽

Lead Oxidation

The initial stages of lead oxidation in a range of alkaline solutions of varying pH and ion content have been investigated with the use of cyclic voltammetry and potential step techniques. In both carbonate and borate buffered solutions (pH > 9), and in more alkaline solutions, Pb oxidation commences at a potential of ca. 140 mV vs. RHE. The initial product is considered to be Pb(OH)2, due to the proximity of this potential with the theoretically predicted one, and due to its invariance (vs. RHE) with pH. In pH 14 solutions, Pb(OH)2 is soluble, producing Pb(OH)3− and only a small amount of a stable surface film. At lower pH's, Pb(OH)2 is not predicted to be soluble, and in borate-buffered solutions, a stable, reducible film appears to form. In carbonate-buffered solutions, the surface film is very difficult to remove electrochemically. Although XPS analyses show the film to be essentially free of carbonate, it is clear that carbonate must be involved in some way in inhibiting film reduction. Keywords: lead, lead hydroxide, lead oxide, surface films, carbonate solutions, borate solutions, alkaline solutions, cyclic voltammetry.

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Nonlinear Neutron and X-Ray Reflectance for Surface Films

MRS Proceedings ◽

10.1557/proc-376-193 ◽

1994 ◽

Vol 376 ◽

Author(s):

Xiao-Lin Zhou

Keyword(s):

Born Approximation ◽

Scattering Length ◽

Surface Film ◽

Recurrence Formula ◽

Arbitrary Point ◽

Surface Films ◽

Exponential Factor ◽

X Ray ◽

Shift Effect ◽

Superposition Approximation

ABSTRACTThis paper presents an analysis of the relationship between Parratt's recurrence formula and several existing analytical formulations for the neutron and x-ray reflectance of a surface film. In particular, it was shown that the Born approximation and the weighted-superposition approximation (WSA) for the neutron and x-ray reflectance can both be derived directly from Parratt's recurrence formula. It was also shown that the well-known nonlinear differential equation for the reflectance at an arbitrary point inside a film can be obtained from Parratt's recurrence formula and the WSA was an approximate solution to this equation. Finally, the nonlinearity in the WSA was discussed through a comparison between the Born approximation and the WSA. It was pointed out that the exponential factor in the WSA correctly accounted for both the phase shift effect due to the scattering length density of the film and the amplitude attenuation effect due to evanescence.

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