  A survey of 28 stars using EUV spectra has been conducted to establish the
structure of stellar coronae in active binary systems from the EMD, electron
densities, and scale sizes. Observations obtained by the EUVE during 9 years of
operation are included for the stars in the sample. EUVE data allow a
continuous EMD to be constructed in the range log T~5.6-7.4, using iron
emission lines. These data are complemented with IUE observations to model the
lower temperature range. Inspection of the EMD shows an outstanding narrow
enhancement, or ``bump'' peaking around log T~6.9 in 25 of the stars, defining
a fundamental coronal structure. The emission measure per unit stellar area
decreases with increasing orbital (or photometric) periods of the target stars;
stars in binaries generally have more material at coronal temperatures than
slowly rotating single stars. High electron densities (Ne>10^12 cm^-3) are
derived at ~10 MK for some targets, implying small emitting volumes. The
observations suggest the magnetic stellar coronae of these stars are consistent
with two basic classes of magnetic loops: solar-like loops with maximum
temperature around log T~6.3 and lower electron densities (Ne>10^9-10.5), and
hotter loops peaking around log T~6.9 with higher electron densities
(Ne>10^12). For the most active stars, material exists at much higher
temperatures (log T>6.9) as well. However, current ab initio stellar loop
models cannot reproduce such a configuration. Analysis of the light curves of
these systems reveals signatures of rotation of coronal material, as well as
apparent seasonal changes in the activity levels.
