a Image fusion allows for the combination of an image containing chemical information but low spatial resolution with a highspatial resolution image having little to no chemical information. The resulting hybrid image retains all the information from the chemically relevant original image, with improved spatial resolution allowing for visual inspection of the spatial correlations. In this research, images were obtained from two sample test grids: one of a copper electron microscope grid with a letter 'A' in the center (referred to below as the 'A-grid'), and the other a Tantalum and Silicon test grid from Cameca that had an inscribed letter 'C' (referred to below as the 'Cameca grid'). These were obtained using scanning electron microscopy (SEM) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Image fusion was implemented with the Munechika algorithm. The edge resolution of the resulting hybrid image was calculated compared with the edge resolution obtained for both the individual ToF-SIMS and SEM images. The challenges of combining complimentary datasets from different instrumental analytical methods are discussed as well as the advantages of having a hybrid image. The distance across the edge for hybrid images of the A-Grid and the Cameca grid were determined to be 21 μm and 8 μm, respectively. When these values were compared to the original ToF-SIMS, SEM and optical microscopy measurements, the fused image had a spatial resolution nearly equal to that obtained in the SEM image for both samples.
Understanding and resolving discrepancies between atom probe tomography (APT) and secondary ion mass spectrometry (SIMS) measurements of B dopants in Si-based materials has long been a problem for those in the semiconductor community who wish to measure B within the source/drain SiGe of a device. APT data collection of Si-based materials is typically optimized for Si, which is logical, but perhaps not ideal for field evaporation of B. Increasing the evaporation field well beyond the typically used 28Si2+:28Si+ ratio of approximately 10:1 up to a ratio of ~200:1 is demonstrated to improve B detection while retaining well-matched Si and Ge concentrations with respect to those measured by SIMS. A range of evaporation conditions are examined from a very low field with high laser energy to an extremely high field with extremely low laser energy demonstrating problems at both far ends of the spectrum and a sweet spot when the operating conditions used produce a 28Si2+:28Si+ ratio of approximately 200:1 (in terms of total counts of each ionization state), which is more than an order of magnitude higher than normally used conditions and results in nicely matched B, Si, and Ge APT measurements with those of SIMS.
Almost half of the total rural area of Guizhou Province and many regions within the 11 adjacent provinces in southwestern China have a long history (at least 70 years) of endemic fluorosis, including dental fluorosis and osteofluorosis along with its associated deformities and disabilities. Over decades of research, this specific type of endemic fluorosis has been defined as coal-burning fluorosis, which is distinct from drinking-water fluorosis. It is generally acknowledged that indoor burning and combustion of high-fluorine coal leads to food contamination, and fluorine then enters the human body. However, the exact chemical form of fluorine during its release and transfer to the body is still unknown. In the present study, 21 domestic coal samples from outcrop and semi-outcrop coal collected in five villages with fluorosis were analyzed by time-of-flight secondary ion mass spectrometry (TOF-SIMS). The total mass fraction of sulfur in the samples ranged from 0.24%-5.58% and total fluorine content ranged 90.2-149.2 mg/kg. H 3 O + , H 2 SO 4 + and HSO 4 were detected in the samples by TOF-SIMS, which indicated that sulfuric acid hydrate (H 2 SO 4 ·H 2 O) was present in the samples. F -was detected in all of these, which suggested the samples contain ionic fluorine compounds. Under certain circumstances, such as heating or burning, the prevalence and coexistence of the acid (H 2 SO 4 ·H 2 O) and base (F -) would lead to a neutralization reaction producing volatile hydrogen fluoride (HF, bp = 19.5°C). This would be the chemical form of fluorine released from the coal. Further studies using HF and SO 2 test tubes on headspace gas over coal samples heated to 200°C in the laboratory and on headspace gas over stoves or chimney tops at rural residences confirmed the release of HF. endemic fluorosis, hydrogen fluoride, sulfuric acid hydrate, time-of-flight secondary ion mass spectrometry, Guizhou Citation: Liang H D, Liang Y C, Gardella J A Jr, et al. Potential release of hydrogen fluoride from domestic coal in endemic fluorosis area in Guizhou, China.
Uranium oxide particles tens of micrometers in size, including natural and depleted UO 2 , U 3 O 8 , and UO 3 were analyzed using an IONTOF V time-of-flight secondary ion mass spectrometry (TOF-SIMS) V. Particulate samples were mounted on gold substrates made using a novel technique that reduced hydrocarbon contamination and volatile outgassing as well as provided an internal standard of Au x ion peaks to calibrate high masses. For UO 2 surfaces, the dominant U 3 O x and U 4 O y cations were U 3 O 6 + and U 4 O 8 + , whereas for both U 3 O 8 and UO 3 surfaces, they were U 3 O 7 + and U 4 O 9 +. Secondary ion abundance ratios contained additional information about the chemical composition of the sample related to the relative stability of the cluster ions. Relative stabilities of the most stable cation isomers corresponding to masses observed in SIMS spectra were calculated using high-level density functional theory in order to compare ion stabilities to TOF-SIMS intensity distributions. Cation isomers having high oxygen content were doublets, and those having low oxygen content were quartet spin states. Depth profile trends for 'protonation' ratio and 'lattice valence', as defined by Plog, Wiedmann, and Benninghoven, were used to distinguish U 3 O 8 from UO 3 . Cations containing a greater number of uranium atoms were also found to have a lower protonation ratio. UO 2 and U 3 O 8 surfaces show a steeper reduction in protonation ratio compared to UO 3 surfaces which exhibit a nearly constant near-surface protonation ratio followed by a more gradual smaller decline with depth. We interpret secondary ion distribution results using density functional quantum mechanics calculations comparing the relative stability of cations and anions for different oxygen atom environments.
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