Ago H, Imamura S, Okazaki T, Saito T, Yumura M, Tsuji M. CVD growth of single-walled carbon nanotubes with narrow diameter distribution over Fe/MgO catalyst and their fluorescence spectroscopy. J Phys Chem B. 2005 May 26;109(20):10035–41. doi: 10.1021/jp050307q. PMID: 16852214.