Quantitative Interleaved-Pulse Acquisition Extends the Range of Isotope-Ratio Measurements in ToF-SIMS

Source data for "Quantitative Interleaved-Pulse Acquisition Extends the Range of Isotope-Ratio Measurements in ToF-SIMS" This record contains the numerical data behind every figure and table of the manuscript and its Supporting Information (Analytical Chemistry, Technical Note, submitted 2026), the figures as submitted, and the per-crater depth profiles and mass spectra exported from the instrument software from which the figure data were computed. The paper describes a method for quantitative isotope-ratio depth profiling by time-of-flight secondary ion mass spectrometry (ToF-SIMS) when the two isotopes differ in intensity by orders of magnitude. Each analysis cycle records two primary-ion pulse widths; the major isotope is taken from the short pulse, where it remains within the linear range of the detector, and the minor isotope from the long pulse, where its counting statistics are better; a dose factor measured within each crater links the two. The data cover thermal SiO₂ at natural ¹⁸O abundance (transfer curves of counts per pulse versus pulse width, peak shapes, dead-time verification, and per-layer precision for several acquisition strategies), ¹⁸O-enriched WOₓ films with buried isotopic markers of 12.5–50% nominal enrichment (depth profiles of the ¹⁸O fraction), and isotope-ratio accuracy data for SiO₂, SrTiO₃ and WOₓ. Measurements were made on an IONTOF TOF.SIMS 5-NCS instrument (SurfaceLab 7.5) in bunched mode with Bi₃⁺ analysis and Cs⁺ sputtering. Files: README.md (file guide, column definitions, conventions); source_data.zip (11 CSV files for Figures 1–3, S1–S2 and Tables 1, 2, S1, each with a provenance header, and the figures as TIF/PNG); exports_SiO2.zip (per-width spectra and per-scan, per-phase depth profiles of the SiO₂ craters); exports_WOx.zip (per-scan depth profiles and windowed spectra of the WOₓ craters); LICENSE; CITATION.cff. Exported counts carry the vendor single-stop Poisson dead-time correction and must not be corrected again. Raw IONTOF project files and analysis scripts are available from the author on request. Funding: U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering. Measurements were performed at the Center for Nanophase Materials Sciences, a U.S. DOE Office of Science User Facility at Oak Ridge National Laboratory. The WOₓ films were provided by Yiyang Li and Heather Hare (University of Michigan).