ANISOTROPIC MAGNETIC PENETRATION DEPTH OF GRAIN-ALIGNED HGBA2CA2CU3O8+DELTA

The temperature (T) dependence of the anisotropic magnetic penetration depth lambda( T) of magnetically aligned powders of crystalline HgBa2 Ca2Cu3O8+delta is reported. Measurements were performed in the Meissne r state using the ac-susceptibility technique. The temperature depende nces of the in-plane, lambda(ab)(T), and out-of-plane, lambda(c)(T), p enetration depths are markedly different. This is believed to arise fr om the large anisotropy ratio gamma=[lambda(c)(0)/lambda(ab)(0)]simila r or equal to 30. The behavior of lambda(ab)(T) is indicative of d-wav e superconductivity while lambda(c)(T) is similar to the behavior expe cted for a superconductor with intrinsic Josephson coupling between th e CuO2 planes. Similar measurements were performed on Ba0.6K0.4BiO3 po wders for comparison.