  The spin-Peierls phase transition in CuGeO_3 has been extensively studied
utilizing a variety of experimental techniques. Interpretations of the phase
transition behavior vary from tricritical to mean field to Ising critical to XY
critical. We show that the behavior in the vicinity of the phase transition of
each of the order parameter, the magnetic energy gap and the heat capacity can
be quantitatively fitted with few adjustable parameters with a mean field model
incorporating a tricritical to mean field critical crossover in the transition
region.
