Recent advances in dual mode charge compensation for XPS analysis

Abstract

Dual mode charge compensation has been used successfully for many years to enable X‐ray photoelectron spectroscopy (XPS) analysis of a variety of insulating samples. This approach uses a combination of low energy electrons and argon to compensate for positive charge build‐up during irradiation by X‐rays. Whilst this method works with no detectable side effects in most cases, it was recently reported that the chemical bonding states of some Cr(VI) oxides may be modified by prolonged exposure to the flood source. In this work, we demonstrate successful dual mode charge compensation of CrO3 with no discernible sample modification from the flood source. Under the same flood source conditions, we extend the analysis to other systems known to undergo reduction and present charge compensated XPS data for V2O5 and a copper‐based metal‐organic framework (MOF) showing little or no modification from the flood source, even with prolonged exposure.

XPS guide: Charge neutralization and binding energy referencing for insulating samples

“…See Fig. 2 of Edwards et al 29 for peaks fits to adequately and inadequately neutralized C 1s spectra from a rough fabric surface. Therefore, it is necessary to identify the occurrence of differential charging within your high-resolution spectra if the intention is to rely on spectra for identifying and quantifying oxidation states / functional groups.…”

In‐doped LiCa2.98MgV3O12 rare‐earth‐free phosphor with a high photoluminescence quantum yield of 67.4%

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New insights into the kinetics of metal|electrolyte interphase growth in solid-state-batteries via an operando XPS analysis - part I: experiments

“…15 To minimize the Ar + ion flux reaching the interface, the extractor voltage of the instrument was reduced to 30 V following the results of a previous study. 16 The Na 0 plating rate was controlled by optimizing the FG parameters: the beam voltage was set to 3 V, and the current was set to 30 μA (the actual electronic current reaching the sample surface was measured using a Faraday cup and a value of ~4.8 μA was found; the Ar + current reaching the surface is ~10 nA).The base pressure of the instrument (FG off) is typically around 1 x 10 -9 mbar and rises to around 1 x 10 -8 mbar when the FG is activated. The change in pressure is related to the introduction of a small volume of Ar gas in the analysis chamber associated with the design of the dual mode flood source.…”