Scaling behavior of the I-V characteristic in YBa2Cu3O7 thin films

[[abstract]]A systematic study of the resistive transition, and the detailed I-V characteristic in magnetic fields of the c-axis oriented thin films revealed that: the critical exponent determined from the linear Log(E)-Log(I) curve, is not a universal constant but depends on the applied magnetic fields and the sample thickness; and a 3D to 2D crossover of the flux motion when the applied field exceeds a critical value which is closely related to the sample thickness. The authors have also extended the study to the YBCO films with Ag-doping. The results show that magnetic field effect on the Tc in the Ag-doped film is reduced compared with that of the undoped film[[fileno]]2010127030011[[department]]物理