VORTEX FLUCTUATION OF GRAIN-ALIGNED HGBA2CA2CU3O8+DELTA

We have measured the reversible magnetization M(H, T) for grain-aligned HgBa2Ca2Cu3O8+delta. Our data exhibit a clear vortex fluctuation about 6 K below the superconducting onset temperature. The derived in-plane magnetic penetration depth lambda(ab)(0) is 1700 angstrom which is similar to those of other high-T(c) superconductors. In addition, the zero-temperature GL coherence length xi(ab)(0) is 22 +/- 5 angstrom, which implies GL parameter K = 77 +/- 13. This kappa is much greater than that of HgBa2CuO6, but similar to that of YBa2Cu3O7.