XPS characterization of mica surfaces processed using a radio-frequency (rf) argon plasma

Abstract

X-ray photoelectron spectroscopy (XPS) has been used to characterize the composition of air-cleaved mica surfaces before and after treatment under a range of different conditions in the argon rf plasma discharge. The changes in the composition of the processed surfaces that have been identified are found to depend strongly on the plasma etching parameters used. When etching was conducted at relatively high power levels ( W), the XPS data demonstrate that the mica surfaces examined have a significant accumulation therein of the heavier elements present, namely aluminium and silicon, whereas the oxygen component on the surface is decreased dramatically. However, no obvious changes in the chemical states of the elements contained in the mica were found for the sample surfaces processed under these conditions. Similar phenomena were also observed when the plasma etching was conducted at higher gas pressures or over prolonged etching times. The various phenomena observed are attributed mainly to the disorganization of the mica surface during etching, namely sputtering followed by re-deposition of the component elements, with loss of oxygen from the surface becoming apparent when the etching parameters were changed as indicated. A relatively high carbon content measured by XPS is always observed on the plasma-etched mica surfaces for which a low silicon content is usually found. The reasons for this behaviour are discussed. The oxygen deficit observed on the argon plasma-etched mica surfaces may be even more significant if one makes allowance for the possible contribution that surface-adsorbed species containing oxygen can make to the oxygen signal.

Tailoring and investigation of surface chemical nature of virgin and ion beam modified muscovite mica

“…It reacts with the Si and Al by breaking of the Si―O and Al―O bonds in the aluminosilicate layer. The breaking of Si―O and Al―O bonds in the aluminosilicate layer was also previously shown after plasma treatment on mica . The TRIM calculations present that the mica surface is modified up to the depth 30 and 60 nm for 12 keV Ar + and N + , respectively; however, sputtering loss of the top surface and chemical changes of mica due to Ar + or N + ion bombardment is not considered in TRIM calculations.…”

“…The energetic ion bombardment on mica substrate is very interesting, as it can change the chemical nature of surface in a controlled way as well as forms a well periodic pattern in nanoscale . However, the studies of surface chemistry of a virgin and an ion or plasma‐treated mica are rare in the literature . Recently, we have reported the scaling properties of ion‐induced ripple patterns and the tunable hydrophobicity of mica surfaces, but the detailed surface chemical investigations of the ion‐modified mica surface and subsequent adsorption of ambient hydrocarbons by the active sites have not been reported.…”

Metastability of anatase: size dependent and irreversible anatase-rutile phase transition in atomic-level precise titania

“…The XPS spectra were measured using a JEOL JPS-9000MC photoelectron spectrometer without the plasma etching process. The binding energy calibration is based on the measurement of the mica O(1s) signal, E b = 531.61 eV53.…”

Effects of H2 Addition in Magnetized Inductively Coupled C2F6 Plasma Etching of Silica Aerogel Film

“…Only two-member ring structure gives an exothermic addition of H 2 to Si-O bonds with the formation of Si-H and O-H groups. 5) In case of high density H 2 plasma treatment, interactions between H 2 , H + , H + 2 , H * , H * 2 , etc and point defects of silica, in particular dangling bonds, and between vacuum ultraviolet (VUV) of 121.5 nm Lyman a line and C-H, C-O, C-C bonds have to be considered.…”

“…The role of VUV in the plasma is an initiation reaction like atomic oxygen particle (ion). 5) Low pressure plasma treatment is increasingly used as an effective method for surface modification. Low pressure plasmas consist of a complex mixture of charged particles (electron, ions) and neutrals.…”