Size dependence of complex refractive index function of growing nanoparticles
|Title||Size dependence of complex refractive index function of growing nanoparticles|
|Publication Type||Journal Article|
|Year of Publication||2011|
|Authors||Eremin, A, Gurentsov, E, Popova, E, Priemchenko, K|
|Journal Title||Applied Physics B: Lasers and Optics|
|Keywords||Electromagnetism, 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.