| Autor: |
J. Wong, S.-N. Yang, S.-N. Mei, Toh-Ming Lu, C.-H. Choi |
| Rok vydání: |
1988 |
| Předmět: |
|
| Zdroj: |
Journal of Crystal Growth. 87:357-364 |
| ISSN: |
0022-0248 |
| DOI: |
10.1016/0022-0248(88)90188-1 |
| Popis: |
An attempt has been made to measure Mg clusters formed by the supersonic jet expansion from a heated crucible using the retarding potential technique. The experiment was performed in a typical ionized cluster beam (ICB) deposition system. With Mg deposition up to 50 A/s on a substrate 30 cm away from the source, we failed to observe abundance of large clusters (≥100 atoms/cluster). Our numerical calculations of the cluster size distribution during supersonic jet expansion based on a step-wise cluster growth model show that for an expansion angle of 20°, large cluster formation becomes appreciable only if the stagnation pressure is larger than 10 Torr. This condition implies a deposition rate of 1000 A/s. This deposition rate is difficult to achieve in a single chamber system without differential pumping. Our results are compared with previous reports on the metal cluster size measurement using retarding potential and other techniques. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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