  We report the identification of 17 candidate brown dwarf binaries whose
components straddle the L dwarf/T dwarf transition. These sources were culled
from a large near-infrared spectral sample of L and T dwarfs observed with the
Infrared Telescope Facility SpeX spectrograph. Candidates were selected on the
basis of spectral ratios which segregate known (resolved) L dwarf/T dwarf pairs
from presumably single sources. Composite templates, constructed by combining
13581 pairs of absolute flux-calibrated spectra, are shown to provide
statistically superior fits to the spectra of our seventeen candidates as
compared to single templates. Ten of these candidates appear to have secondary
components that are significantly brighter than their primaries over the
1.0-1.3 micron band, indicative of rapid condensate depletion at the L dwarf/T
dwarf transition. Our results support prior indications of enhanced
multiplicity amongst early-type T dwarfs; 53+/-7% of the T0-T4 dwarfs in our
spectral sample are found to be either resolved or unresolved (candidate)
pairs, although this is consistent with an intrinsic (volume complete) brown
dwarf binary fraction of only 15%. If verified, this sample of spectral
binaries more than doubles the number of known L dwarf/T dwarf transition
pairs, enabling a broader exploration of this poorly-understood phase of brown
dwarf atmospheric evolution.
