A heat capacity investigation of the soliton lattice in the high-field incommensurate phase of CuGeO3

We report on a heat capacity investigation of the spin-Peierls compound CuG eO3 by magnetic field sweeps up to 27 T at fixed temperatures. In the dimer ized phase the heat capacity exhibits a simple quadratic field dependence. In contrast, non-monotonous variations occur in the incommensurate phase, w ith characteristic plateaus separated by steps or smoother variations, depe nding on the quality of the samples. Such a plateau-type structure is attri buted to the dynamics of solitons where a pinning mechanism blocks the cont inuous rearrangement of the soliton lattice driven by the magnetic field.