Electron-probe microanalysis of porous materials
| Autor: | Charles E. Lyman, Joseph I. Goldstein, Rollin E. Lakis |
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| Rok vydání: | 1992 |
| Předmět: | |
| Zdroj: | Proceedings, annual meeting, Electron Microscopy Society of America. 50:1660-1661 |
| ISSN: | 2690-1315 0424-8201 |
| Popis: | Conventional electron probe microanalysis (EPMA) requires solid, flat-polished specimens, and similarly prepared standards of known composition. Unfortunately, an increasing number of technologically important materials are particulate in nature and contain significant porosity. Supported heterogeneous catalysts are an important example. Many catalysts of industrial importance consist of a number of active metals and promoters dispersed in a porous (50% theoretical density, 200 m2/g surface area) ceramic support material. It is of great practical interest to determine the concentration and precise location of each component within the support material, but quantitative EPMA has typically been avoided because of the bulk porosity and surface roughness. In order to assess the effects which porosity and the accompanying surface roughness have upon quantitative EPMA, two types of model porous specimens were prepared; one an insulator (alpha alumina) and the other a conductor (silver). The alumina specimens (Figure l.)were prepared to between 57% theoretical density and full density by controlled sintering of 0.3 μm alumina powder. |
| Databáze: | OpenAIRE |
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