TY - JOUR TI - Independent evaluation of conflicting microspherule results from different investigations of the Younger Dryas impact hypothesis AU - LeCompte, M. A. AU - Goodyear, A. C. AU - Demitroff, M. N. AU - Batchelor, D. AU - Vogel, E. K. AU - Mooney, C. AU - Rock, B. N. AU - Seidel, A. W. T2 - Proceedings of the National Academy of Sciences of the United States of America DA - 2012/// PY - 2012/// VL - 109 IS - 44 SP - E2960-2969 ER - TY - JOUR TI - Time-of-Flight-Secondary Ion Mass Spectrometry Method Development for High-Sensitivity Analysis of Acid Dyes in Nylon Fibers AU - Zhou, Chuanzhen AU - Li, Min AU - Garcia, Roberto AU - Crawford, Anne AU - Beck, Keith AU - Hinks, David AU - Griffis, Dieter P. T2 - ANALYTICAL CHEMISTRY AB - A minimally destructive technique for the determination of dyes in finished fibers provides an important tool for crime scene and other forensic investigations. The analytical power and the minimal sample consumption of time-of-flight-secondary ion mass spectrometric (TOF-SIMS) analysis provides the ability to obtain definitive molecular and elemental information relevant to fiber identification, including identification of dyes, from a very small volume of sample. For both fiber surface analysis and, with the aid of cryomicrotomy, fiber cross-section analysis, TOF-SIMS was used to identify various dyes in finished textile fibers. The analysis of C.I. Acid Blue 25 in nylon is presented as a representative example. The molecular ion of C.I. Acid Blue 25 with lower than 3% on weight-of-fiber (owf) dye loading cannot be identified on dyed nylon surfaces by TOF-SIMS using a Bi3+ primary ion beam. Sputtering with C60+ provided the ability to remove surface contamination as well as at least partially remove Bi-induced damage, resulting in a greatly improved signal-to-noise ratio for the Acid Blue 25 molecular ion. The use of C60+ for damage removal in a cyclic manner along with Bi for data acquisition provided the ability to unambiguously identify Acid Blue 25 via its molecular ion at a concentration of 0.1% owf from both fiber surfaces and cross sections. DA - 2012/11/20/ PY - 2012/11/20/ DO - 10.1021/ac3025569 VL - 84 IS - 22 SP - 10085-10090 SN - 1520-6882 ER - TY - JOUR TI - Quantification of cesium surface contamination on silicon resulting from SIMS analysis AU - Penley, C. AU - Stevie, F. A. AU - Griffis, D. P. T2 - JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B AB - In order to improve the understanding of unintended cesium (Cs) contamination that occurs during SIMS depth profiling, Cs concentrations on sample surfaces were measured before analysis and at various distances from a depth profile crater after analysis. Cs concentrations in excess of 1 at. % were found directly adjacent to the depth profile analysis site. Cs was also detected at significant concentrations hundreds of micrometers from the depth profile measurement location. This Cs contamination can originate from a number of sources including Cs beam tails, Cs neutral beam, and secondary sputtering from instrument optics and other structures. Since the presence of cesium significantly affects the secondary ion yield of electronegative elements (e.g., phosphorus) in silicon, the unintended presence of cesium on the surface of a previously analyzed sample can strongly affect the reproducibility and accuracy of low dose electronegative element measurements, especially at the surface. DA - 2012/// PY - 2012/// DO - 10.1116/1.3698400 VL - 30 IS - 3 SP - SN - 2166-2746 ER - TY - JOUR TI - Strain effects on the crystal growth and superconducting properties of epitaxial niobium ultrathin films AU - Clavero, C. AU - Beringer, D. B. AU - Roach, W. M. AU - Skuza, J. R. AU - Wong, K. C. AU - Batchelor, A. D. AU - Reece, C. E. AU - Lukaszew, R. A. T2 - Crystal Growth and Design DA - 2012/// PY - 2012/// VL - 12 IS - 5 SP - 2588-2593 ER -