Hole-filling above T-c, at the origin of the in-plane resistivity anomaly in Bi-2212 crystals

We have observed a sharp peak (100%) in the in-plane resistivity rho(ab) ju st above T-c, in Bi-2212 crystals, in agreement with previous results from Han et al. who attributed this anomaly to the "quasi-reentrant behaviour" a lready observed for polycrystalline samples. This explanation is very likel y unadapted to these crystals and we propose another one related to a model we had used to fit rho(c)(T) curves for Bi-2212 underdoped crystals, namel y, an increase of the Fermi level (hole-filling) with decreasing temperatur e, above T-c, probably due to a change in the Bi-O or Cu-O bonds. A previou sly reported c-axis lattice anomaly, occurring in the same temperature rang e, is most probably related to this bonding alteration.