Anisotropic specific heat behaviour under magnetic field of single crystal YBa2Cu3O7

Specific heat experiments have been performed on single crystal YBa 2 Cu 3 O , around the transition, under magnetic fields up to 6 tesla orientated parallel and normal to the (ab) planes. The curves under field {ie1343-01} (ab) show a weak influence of the field on the Cp anomaly, by comparison with the smearing effect observed when the field is normal to the (ab) planes. The results are consistent with the recent magnetic data of the literature, which alow us to calculate the anisotropy of the Cp discontinuity and the entropy changes under field.