ИСТИНА

We focus on behaviour of Pd0.99Fe0.01 ferromagnetic layer integrated in superconductor/ferromagnet/superconductor (SFS) tunnel Josephson considered for application as a magnetic memory element. A Pd0.99Fe0.01 ferromagnetic tunneling barrier possesses an in-plane magnetic anisotropy and small coercive field. An application of small external magnetic field changes the magnetization of ferromagnetic layer that in turn changes the junction critical current Ic, allowing the realization of two distinct states with high and low Ic corresponding to logical “0” and logical “1” states respectively [1-3]. Dynamical properties (i.e. gyromagnetic ratio, Gilbert damping constant, etc.) of Pd0.99Fe0.01 ferromagnetic layer are investigated employing high sensitive ferromagnetic resonance experiment [4]. A characteristic time scale for magnetization dynamics obtained is 2−3×10-9 s according to natural FMR frequency. Next we examine a numerical approach for simulation of critical current dependence on applied magnetic field in SFS junctions with inplane magnetization. This approach is based on micromagnetic simulation of remagnetization process of ferromagnetic layer and subsequent reconstruction of the critical current value using total flux (fluxometric) or global least squares (GLS) reconstructed actual phase difference distribution. The approach allows to predict the Ic(H) dependence for SFS junction of random shape and magnetic field orientation and enables to consider rectangular SFS memory element with logical states realized via orientation of saturated magnetic moment. Authors acknowledge the Russian Foundation for Basic Research (RFBR) (research projects No. 16-32-00309 and No. 16-32-60133), the Ministry of Education and Science of the Russian Federation in the framework of Increase Competitiveness Program of NUST “MISiS” (research projects No. K4-2014-080 and No. K2-2014-025). The STM studies has been supported by Russian Science Foundation project No. 15-12-30030. V.S. acknowledges partial support by the Program of Competitive Growth of Kazan Federal University. D.R. acknowledges the support from the French Research Agency (ANR) in the framework of MISTRAL project. [1] V. V. Bol’ginov et al., JETP Lett. 95, 366 (2012). [2] V. V. Ryazanov et al., Physics Procedia 36, 35 (2012). [3] I. V. Vernik et al., IEEE Trans. Appl. Supercond. 23, 1701208 (2013). [4] I. A. Golovchanskiy et al., submitted to Journal of Applied Physics (2016).