Characterization of solid standards prepared by freeze-drying
| Autor: | T. J. Bard, H.-J. Lunk, T. A. Frisk, T. A. Dang, S. Roychowdhury |
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| Rok vydání: | 2009 |
| Předmět: |
Glow Discharge Mass Spectrometry
Dopant Chemistry Doping Analytical chemistry chemistry.chemical_element Surfaces and Interfaces General Chemistry Tungsten Condensed Matter Physics Homogeneous distribution Surfaces Coatings and Films Freeze-drying Homogeneity (physics) Materials Chemistry Sublimation (phase transition) |
| Zdroj: | Surface and Interface Analysis. 42:45-51 |
| ISSN: | 0142-2421 |
| DOI: | 10.1002/sia.3145 |
| Popis: | Solid standards prepared by freeze-drying consistently showed a high degree of homogeneity. The freezing process, completed in fractions of a second, preserves the original homogeneous distribution of the dopants, and the subsequent sublimation step would minimize any disturbance. Compared to those prepared by conventional methods such as blending and spiking, freeze-dried standards exhibited superior lateral distribution and better uniform depth distribution. There is, however, a concentration constraint for achieving homogeneity. At 5% doping, segregation was observed in both lateral and depth distribution. Many tungsten standards doped with 10–28 elements ranging from 10 to 200 ppm were successfully prepared and used as controls for a number of analytical techniques including glow discharge mass spectrometry (GDMS) and d.c.-arc optical emission spectroscopy (OES). Copyright © 2009 John Wiley & Sons, Ltd. |
| Databáze: | OpenAIRE |
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