 The discovery of carbon nanotubes is largely attributed to Sumio Iijima of NEC in 1991, although carbon nanotubes have been produced and observed under a variety of conditions prior to 1991.Iijima's discovery of multi-walled carbon nanotubes in the insoluble material of arc-burned graphite rods in 1991 and Mintmire, Dunlap, and White's independent prediction that if single-walled carbon nanotubes could be made, then they would exhibit remarkable conducting properties helped create the initial buzz that is now associated with carbon nanotubes.Nanotube research accelerated greatly following the independent discoveries by Bethune at IBM and Iijima at NEC of "single-walled" carbon nanotubes and methods to specifically produce them by adding transition-metal catalysts to the carbon in an arc discharge.