The adsorption of H2O vs O2 on beryllium

S. Zalkind; M. Polak; N. Shamir

doi:10.1016/S0039-6028(97)00223-9

The adsorption of H₂O vs O₂ on beryllium

S. Zalkind, M. Polak, N. Shamir

Department of Chemistry

Research output: Contribution to journal › Article › peer-review

30 Scopus citations

Abstract

The adsorption mechanism and initial oxidation of sputtered beryllium exposed to H₂O and to O₂ were studied using a combination of the DRS, AES and XPS techniques. For both cases, the "clustering" Langmuir type mechanism was found to fit the adsorption kinetics. The initial sticking coefficients, estimated from these fits, are S_0(H2O) ≈ 1 S0_(O2) ≈ 0.07. Oxide islands, ∼ 3 monolayers thick, are formed in both cases, spreading laterally till a full layer is formed. For O₂ the oxidation stops at this stage, while for H₂O it continues at a lower rate, reaching a saturation level of about six monolayers. Observation of significant broadening of the AES O KVV peak in the stage of thickness growth for the H₂O exposure, and DRS H depth profiling indicate that hydrogen is trapped in the oxide matrix. Possible hydrogen-enhanced-diffusion of ions through the oxide seems to enable the further growth.

Original language	English
Pages (from-to)	318-327
Number of pages	10
Journal	Surface Science
Volume	385
Issue number	2-3
DOIs	https://doi.org/10.1016/S0039-6028(97)00223-9
State	Published - 10 Aug 1997

Keywords

Adsorption kinetics
Auger electron spectroscopy
Beryllium
Oxidation
Oxygen
Water

ASJC Scopus subject areas

Condensed Matter Physics
Surfaces and Interfaces
Surfaces, Coatings and Films
Materials Chemistry

Access to Document

10.1016/S0039-6028(97)00223-9

Cite this

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title = "The adsorption of H2O vs O2 on beryllium",

abstract = "The adsorption mechanism and initial oxidation of sputtered beryllium exposed to H2O and to O2 were studied using a combination of the DRS, AES and XPS techniques. For both cases, the {"}clustering{"} Langmuir type mechanism was found to fit the adsorption kinetics. The initial sticking coefficients, estimated from these fits, are S0(H2O) ≈ 1 S0(O2) ≈ 0.07. Oxide islands, ∼ 3 monolayers thick, are formed in both cases, spreading laterally till a full layer is formed. For O2 the oxidation stops at this stage, while for H2O it continues at a lower rate, reaching a saturation level of about six monolayers. Observation of significant broadening of the AES O KVV peak in the stage of thickness growth for the H2O exposure, and DRS H depth profiling indicate that hydrogen is trapped in the oxide matrix. Possible hydrogen-enhanced-diffusion of ions through the oxide seems to enable the further growth.",

keywords = "Adsorption kinetics, Auger electron spectroscopy, Beryllium, Oxidation, Oxygen, Water",

author = "S. Zalkind and M. Polak and N. Shamir",

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T1 - The adsorption of H2O vs O2 on beryllium

AU - Zalkind, S.

AU - Polak, M.

AU - Shamir, N.

PY - 1997/8/10

Y1 - 1997/8/10

N2 - The adsorption mechanism and initial oxidation of sputtered beryllium exposed to H2O and to O2 were studied using a combination of the DRS, AES and XPS techniques. For both cases, the "clustering" Langmuir type mechanism was found to fit the adsorption kinetics. The initial sticking coefficients, estimated from these fits, are S0(H2O) ≈ 1 S0(O2) ≈ 0.07. Oxide islands, ∼ 3 monolayers thick, are formed in both cases, spreading laterally till a full layer is formed. For O2 the oxidation stops at this stage, while for H2O it continues at a lower rate, reaching a saturation level of about six monolayers. Observation of significant broadening of the AES O KVV peak in the stage of thickness growth for the H2O exposure, and DRS H depth profiling indicate that hydrogen is trapped in the oxide matrix. Possible hydrogen-enhanced-diffusion of ions through the oxide seems to enable the further growth.

AB - The adsorption mechanism and initial oxidation of sputtered beryllium exposed to H2O and to O2 were studied using a combination of the DRS, AES and XPS techniques. For both cases, the "clustering" Langmuir type mechanism was found to fit the adsorption kinetics. The initial sticking coefficients, estimated from these fits, are S0(H2O) ≈ 1 S0(O2) ≈ 0.07. Oxide islands, ∼ 3 monolayers thick, are formed in both cases, spreading laterally till a full layer is formed. For O2 the oxidation stops at this stage, while for H2O it continues at a lower rate, reaching a saturation level of about six monolayers. Observation of significant broadening of the AES O KVV peak in the stage of thickness growth for the H2O exposure, and DRS H depth profiling indicate that hydrogen is trapped in the oxide matrix. Possible hydrogen-enhanced-diffusion of ions through the oxide seems to enable the further growth.

KW - Adsorption kinetics

KW - Auger electron spectroscopy

KW - Beryllium

KW - Oxidation

KW - Oxygen

KW - Water

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DO - 10.1016/S0039-6028(97)00223-9

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JO - Surface Science

JF - Surface Science

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