EFFECTS OF ZN DOPING ON THE ANISOTROPIC PENETRATION DEPTH OF YBA2CU3O7

We have investigated the temperature (T) and doping dependences of the anisotropic magnetic penetration depth lambda of high-quality grain-a ligned YBa2(Cu1-xZnx)(3)O-7 with x=0.00, 0.02, 0.03, and 0.05 using th e ac-susceptibility technique. The values of the in-plane, lambda(ab)( 0), and out-of-plane, lambda(c)(0), penetration depths were found to i ncrease strongly with increased Zn concentration whereas the anisotrop y gamma=[lambda(c)(0)/lambda(ab)(0)] decreased. With increased Zn dopi ng the [lambda(ab)(0)/lambda(ab)(T)](2) and [lambda(c)(0)/lambda(c)(T) ](2) systematically approach each other.