Abstract
The field-emission characteristics of individual ropes made of B-C-N nanotubes were measured in situ in a low-energy electron point source microscope. The tungsten field emission tip of the microscope was used as a movable electrode, approaching the rope, and acting as an anode during field-emission measurements. The atomic structure and chemical composition of the ropes were analyzed by high-resolution transmission electron microscopy and electron energy-loss spectroscopy. The tubes assembled within the ropes typically revealed open-tip ends, a small number of layers and zigzag chirality. We found that the field-emission properties of the B-C-N nanotube ropes are competitive with conventional C nanotubes, with the expected additional benefit that the B-C-N ropes exhibit higher environmental stability. (C) 2002 American Institute of Physics.