PUB - Publikationen an der Universität Bielefeld

The temperature dependence of saturation and spin-flop fields for artificial ferrimagnets (AFi) based on antiparallel coupled CoFeB/Ru/CoFeB trilayers has been investigated in a temperature range between 80 K and 600 K. The results presented in this paper are relevant for magnetic devices using this system, e.g. magnetic-random access memory based on spin-flop switching. In good accordance to the theory, the saturation field H-sat, behaves like H-sat proportional to H-0 (T/T-0)/sinh(T/T-0) with a characteristic temperature of T-0 approximate to 150 K. Within this model, the Fermi velocity for the Ru laver is of the order of 10(5) m/s, therefore, explaining the strong variation of the coupling strength with the temperature in Ru-based AFi. Furthermore, a strong uniaxial anisotropy of K-u = 2 x 10(3) J/m(3) with a small angular distribution of the anisotropy axes is observed for the AFi trilayers based on amorphous CoFeB alloys. Copyright (C) EPLA, 2007