We present experimental studies of static and dynamic properties of 0, $\pi$, and $0\text{−}\pi$ superconductor-insulator-ferromagnet-superconductor (SIFS) Josephson junctions of small and intermediate length. In the underdamped limit, these junctions exhibit a rich dynamical behavior such as resonant steps on the current-voltage characteristics. Varying the experimental conditions, zero-field steps, Fiske steps, and Shapiro steps are observed with a high resolution. A strong signature of the $0\text{−}\pi$ Josephson junction is demonstrated by measuring the critical current as a function of two components ($B_x$ and $B_y$) of an in-plane magnetic field. The experimental observation of a half-integer zero-field step in $0\text{−}\pi$ SIFS junctions is presented.

• Received 18 January 2008

DOI:https://doi.org/10.1103/PhysRevB.77.214506