STUDY OF INITIAL DUST FORMATION IN AN AR-SIH4 DISCHARGE BY LASER-INDUCED PARTICLE EXPLOSIVE EVAPORATION

Citation
L. Boufendi et al., STUDY OF INITIAL DUST FORMATION IN AN AR-SIH4 DISCHARGE BY LASER-INDUCED PARTICLE EXPLOSIVE EVAPORATION, Journal of applied physics, 76(1), 1994, pp. 148-153
Citations number
19
Categorie Soggetti
Physics, Applied
Journal title
ISSN journal
00218979
Volume
76
Issue
1
Year of publication
1994
Pages
148 - 153
Database
ISI
SICI code
0021-8979(1994)76:1<148:SOIDFI>2.0.ZU;2-6
Abstract
The initial step of particulate growth in a dust forming low pressure radio-frequency discharge has been studied in situ by laser induced pa rticle explosive evaporation (LIPEE). With respect to the conventional light scattering, this method has been found much more efficient to o bserve small nanometer size particles, especially in the case of UV ex cimer laser radiation. Experimental results interpreted by a simple mo del of laser-particle interaction show that the intensity of LIPEE con tinuum emission depends on the particle radius roughly as r4. This int eraction is essentially different from Rayleigh scattering, as the lat ter varies as r6. A study of time evolution of powder formation by LIP EE emission reveals the initial formation of nanometer size crystallit es and the coalescence process leading to larger scale particles. It c ould be demonstrated that the critical step of dust formation is the i nitial clustering process leading to nanometer scale crystallites.