Martinoli, P.Flueckiger, Ph.Marsico, V.Srivastava, P.K.Leemann, Ch.Gavilano, J.L.2005-10-182005-10-18199010.1016/S0921-4526(09)80167-1https://infoscience.epfl.ch/handle/20.500.14299/217919The low frequency complex ac impedance Z of c-axis oriented YBa2Cu3O7 thin films was measured as a function of the applied magnetic field B. At temperatures not too close to the transition temperature the imaginary part of Z is proportional to B2, while the real part consists of a term proportional to B3 and an additional term proportional to exp(-1/B) which appears at higher fields. This behavior is in agreement with a description of vortex dynamics with a Langevin equation of motion.text::journal::journal article::research article