Department of Chemistry, National Taiwan UniversitySheu, S.Y.S.Y.SheuLee, I.P.I.P.LeeLee, Y.T.Y.T.LeeChang, H.C.H.C.Chang2006-11-152018-07-102006-11-152018-07-102002-12-10http://ntur.lib.ntu.edu.tw//handle/246246/2006111501221963The formation & size of interstellar diamonds have been investigated by infrared spectroscopy in the laboratory. Employing hot-filament chemical vapor deposition (CVD) to synthesize the interstellar analogs, we successfully reproduced the infrared emission bands of nanodiamonds around HD 97048 & Elias 1. Analysis of the infrared absorption spectra of synthetic diamond crystallites (25–700 nm) from a commercial source reveals a strong size-dependent effect. The 3.53 mm feature emerges only for particles larger than 25 nm. Our experiments suggest that the carriers of the anomalous infrared emission bands at 3.43 & 3.53 mm could be nanodiamonds that are larger than 25 nm & are formed by a CVD-like process.application/pdf83308 bytesapplication/pdfzh-TWjournal article10.1086/345519http://ntur.lib.ntu.edu.tw/bitstream/246246/2006111501221963/1/7822.pdf