Properties of S/N Multilayers with Different Geometrical Symmetry

摘要

The influence of finite dimensions of superconducting metallic multilayers on the H-T phase diagram and angular dependences of the upper critical magnetic field H_(c2) is studied. It is established experimentally that the geometrical symmetry determines crucially the H_(c2) values and their temperature and angular dependencies. For multilayers with the symmetry plane in the center of the superconducting layer and for temperatures close to T_c the values of the parallel critical magnetic fields are larger than for the samples for which the symmetry plane lies in the middle of the normal layer. This reveals the characteristic feature of bi-dimensional behavior in the whole temperature range up to T_c. The angular dependencies of the upper critical magnetic field seem to be more sensitive to the presence of the S/N interfaces in the system than the temperature dependencies.