The newest IONTOF instruments feature several sputter sources that can be used for depth profiling.One of the sources, an O₂-Gas Cluster source, is not commonly used.However, we have found it invaluable when sputtering into insulating materials, like glass, where it is important to preserve the fidelity of the profiles of alkali and other mobile species.Data will be shown illustrating the value of different ion beams for measurements of a variety of species, even at trace levels.

Depth profiles of sputtered coatings are performed commonly, but can be problematic for a variety of reasons, not only due to sputtering artefacts.Use of low energy ion beams and cluster ion beams allows improved resolution and sensitivity.In addition, ToF-SIMS depth profiles can show previously unnoticed contaminants both in the bulk of each layer as well as between layers.Contaminants can be significant if they affect interlayer adhesion and other properties.Some examples will be shown and discussed.

High entropy alloys (HEAs) are known to be composed of five or more principle elements with concentration commonly in equal or near-equal atomic percent. The application of HEAs has substantially gained attention in recent years due to greater fracture resistance, tensile strength and corrosion resistance than conventional alloys. Researchers have developed HEAs with various components in order to strengthen the desirable mechanical or other properties for industrial applications, such as nuclear and aerospace fields. Corrosion resistance is one of important properties to design novel HEA materials, because the cost of corrosion is known to decrease the gross domestic product (GDP) and has no good to economic benefit of industries. With the entropy increase of a larger number of elements in the mix, HEAs shows a stable solid solution phase with no intermetallic phases. The random arrangement of multiple elements results in a particular locally-disordered chemical environment, which leads to unique corrosion-resistance properties. To investigate the corrosion behavior of designed HEA materials, surface characterization on the corrosion area of HEAs is necessary. In this work, hard X-ray photoelectron spectroscopy (HAXPES) and time-of-flight secondary ion mass spectroscopy (ToF-SIMS) are utilized to examine the corrosion behaviors of a commercial AlFeCoCrNi (AFCCN) HEA under sea water or sulfuric acid treatment. Using HAXPES analysis, the greater energy range (Cr Kα 5414.8 eV) allows us to study the chemical state of alloys without Auger peaks interference in conventional XPS. Also its deeper detection depth (~30 nm) enables us to examine the thicker surface oxidized/passivated layer of corrosion area without the concern of sputter damage. Using ToF-SIMS analysis, the chemical imaging and the surface morphology of HEAs corroded area can be observed. With the information of chemical state quantification and chemical imaging, the combination of HAXPES and ToF-SIMS analyses facilitates better understanding on the variation of HEAs surface before and after corrosion.