MAGNETIZATION AND ANISOTROPY OF A HGBA2CA2CU3O8-CRYSTAL(DELTA SINGLE)

From torque measurements as a function of the angle and the magnetic f ield, we extract the magnetization curves and the anisotropy factor fo r a HgBa2Ca2Cu3O8+delta single crystal. The anisotropy is found gamma = 52 +/- 3; it is similar to the one found for the HgBa2Ca3Cu4O10+delt a compound by Zech et al. The analysis of the magnetization close to H -c2(T) within the fluctuations theory yields the critical fluctuations parameter tau(f)=(3.9 +/- 0.4) 10(-2) and the in-plane penetration de pth lambda(0)= 1500 +/- 100 A. The superconducting planes separation i s found of the order of the unit cell length. The upper critical field is estimated (d H-c2/dT)T-c0 approximate to 14 kOe K-1.