Janu Z.,ASCR Institute of Physics Prague |
Svindrych Z.,ASCR Institute of Physics Prague |
Trunecek O.,Charles University |
Kus P.,Komenius University in Bratislava |
Plecenik A.,Komenius University in Bratislava
Physica C: Superconductivity and its Applications | Year: 2011
Thin films of type I superconductors of a thickness comparable or less than a flux penetration length behave like type II superconductors in a mixed state. With decreasing film thickness normal domains carrying a magnetic flux get smaller with smaller number of flux quanta per domain and finally transform into single quantum flux lines, i.e. quantum vortices similar to those found in type II superconductors. We give an evidence of this behavior from the measurements of the nonlinear response of a total magnetic moment to an applied AC magnetic field, directly from the temperature dependence of an AC susceptibility. © 2011 Elsevier B.V. All rights reserved.