Origin of field-dependent optical transmission of magnetic fluid films

Citation
Sy. Yang et al., Origin of field-dependent optical transmission of magnetic fluid films, APPL PHYS L, 79(15), 2001, pp. 2372-2374
Citations number
11
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
APPLIED PHYSICS LETTERS
ISSN journal
0003-6951 → ACNP
Volume
79
Issue
15
Year of publication
2001
Pages
2372 - 2374
Database
ISI
SICI code
0003-6951(20011008)79:15<2372:OOFOTO>2.0.ZU;2-Q
Abstract
The physical mechanism of the optical transmission of magnetic fluid films under perpendicular magnetic fields is investigated in this work. Under per pendicular magnetic fields, originally dispersed magnetic particles agglome rate to form magnetic columns. The liquid phase is transparent, whereas the columns are opaque. Hence, the liquid phase dominates the optical transmis sion of the magnetic fluid film. When the field strength is raised, more co lumns are formed, and the area of the liquid phase is reduced. This leads t o the decrease in the optical transmission of the film under higher field s trength. The variation in the concentration of the liquid phase under vario us field strengths also contributes to the transmission of the film. By tak ing account of the variations of the effective concentration and the area r atio of the liquid phase in the magnetic fluid film under magnetic fields, the resultant magnetic field dependence of the optical transmission was cal culated and found to be consistent with the experimental results. This prov ides evidence for the origin of the field-dependent optical transmission of the magnetic fluid film under external fields. (C) 2001 American Institute of Physics.