Size dependence of complex refractive index function of growing nanoparticles

TitleSize dependence of complex refractive index function of growing nanoparticles
Publication TypeJournal Article
Year of Publication2011
AuthorsEremin, A, Gurentsov, E, Popova, E, Priemchenko, K
Journal TitleApplied Physics B: Lasers and Optics
Start Page285
KeywordsElectromagnetism, Optics and Lasers; Laser Technology and Physics and Photonics; Optical Spectroscopy and Ultrafast Optics; Physical Chemistry; Physics; Physics and Applied Physics in Engineering; Quantum Optics, Quantum Electronics and Nonlinear Optics

The evidence of the change of the complex refractive index function E ( m ) of carbon and iron nanoparticles as a function of their size was found from two-color time-resolved laser-induced incandescence (TiRe-LII) measurements. Growing carbon particles were observed from acetylene pyrolysis behind a shock wave and iron particles were synthesized by pulse Kr–F excimer laser photo-dissociation of Fe(CO) 5 . The magnitudes of refractive index function were found through the fitting of two independently measured values of particle heat up temperature, determined by two-color pyrometry and from the known energy of the laser pulse and the E ( m ) variation. Small carbon particles of about 1–14 nm in diameter had a low value of E ( m )∼0.05–0.07, which tends to increase up to a value of 0.2–0.25 during particle growth up to 20 nm. Similar behavior for iron particles resulted in E ( m ) rise from ∼0.1 for particles 1–3 nm in diameter up to ∼0.2 for particles >12 nm in diameter.