Depth profiling of non-conductive oxidic multilayers with plasma-based SNMS in HF-mode

Basaltic lava from Kilauea, Hawaii may have a red-brown surface, indicative of Fe-(hydr)oxides. This surface is not found where exposed to weathering, but at the interface between lava lobes, or in the interior of lava channels. We use several analytical techniques to determine how these Fe-(hydr)oxide surfaces may have developed. WDS-elemental distribution line profiles from the lava surface towards the lava´s interior detect an Fe-rich film of less than 5 μm thickness. Heat treatment of quenched, fresh lava samples of the same chemical composition between 600-1,090°C helps to replicate temperatures under which such an Fe-rich film might have formed. These experiments suggest that Fe-enrichment occurs above 1,020°C, whereas at lower temperatures Ca is enriched relative to Fe. One sample was treated below the glass transition temperature, at 600°C for 164 h. A depth profile with secondary neutral mass spectrometry shows an enrichment of Mg at the outer 50 nm of the glass surface. The formation of films requires cation migration, which is driven by an oxygen chemical potential between air and the reduced basalt (Fe 2+ /Fe 3+ ratio of 13.3). The change of surface alteration from Mg to Ca film at lower temperatures, to predominantly Fe at high temperatures, is determined by a change of cation availability, largely controlled by crystallization that already occurs below 850°C, and volume crystallization that occurs above 925°C.

show abstract

“…The detection limit is 10 ppm. Some further details regarding the technique are in Goschnick et al (1998). …”

Section: Methodsmentioning

confidence: 99%

Surface alteration of basalt due to cation-migration

Burkhard

Müller-Sigmund

2006

Bull Volcanol

View full text Add to dashboard Cite

show abstract

“…SIMS and SNMS allow depth profile analysis with a depth resolution in the low-nanometre range of hard coatings [93], atmospheric aerosol particles (with aerodynamic diameters on the order of 25-200 nm) [94], nano-objects (nanowhiskers consist of fibres of about 2-nm diameter) [95] and nanoscale multilayers [96][97][98][99][100]. Figure 5 shows the depth profiles obtained by SNMS for a triple-layer system used for gas sensor microdevices (Fig.…”

Section: Secondary Ion Mass Spectrometry and Sputtered Neutral Mass Smentioning

confidence: 99%

Inorganic mass spectrometry as a tool for characterisation at the nanoscale

et al. 2009

View full text Add to dashboard Cite

Inorganic mass spectrometry techniques may offer great potential for the characterisation at the nanoscale, because they provide unique elemental information of great value for a better understanding of processes occurring at nanometre-length dimensions. Two main groups of techniques are reviewed: those allowing direct solid analysis with spatial resolution capabilities, i.e. lateral (imaging) and/or indepth profile, and those for the analysis of liquids containing colloids. In this context, the present capabilities of widespread elemental mass spectrometry techniques such as laser ablation coupled with inductively coupled plasma mass spectrometry (ICP-MS), glow discharge mass spectrometry and secondary ion/neutral mass spectrometry are described and compared through selected examples from various scientific fields. On the other hand, approaches for the characterisation (i.e. size, composition, presence of impurities, etc.) of colloidal solutions containing nanoparticles by the well-established ICP-MS technique are described. In this latter case, the capabilities derived from the on-line coupling of separation techniques such as field-flow fractionation and liquid chromatography with ICP-MS are also assessed. Finally, appealing trends using ICP-MS for bioassays with biomolecules labelled with nanoparticles are delineated.

show abstract