MEAN-FIELD SPECIFIC-HEAT OF CUGEO3

We have measured the specific heat of CuGeO3 using ac calorimetry. The re is a sharp discontinuity at its spin-Peierls phase transition (T-c = 14 K); the magnitude of the jump is consistent with mean-field theor y, and implies a nearest neighbor exchange interaction of 75 K. The ra tio of the specific heat peak and temperature derivative of the magnet ic susceptibility at T-c is consistent with the observed value of d(2) T(c)/dH(2), but this ratio and the activated behavior of c(P) below th e transition deviate from mean-field behavior.