We report an approach to altering the magnetic properties of ͑111͒ textured Co/ Pt multilayer films grown on sapphire ͑0001͒ substrates in a controlled way using single-pulse laser irradiation. The as-grown films reveal a strong perpendicular magnetic anisotropy induced by interfacial anisotropy. We show that laser irradiation can chemically mix the multilayer structure particularly at the interfaces, hence reducing the perpendicular magnetic anisotropy and coercivity in a controlled manner depending on laser fluence. As a result, perpendicular films can also be magnetically patterned into hard and soft magnetic regions using a regular two-dimensional lattice of polystyrene particles acting as an array of microlenses.

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The rapid fire railgun (RAFIRA), a unique railgun that can be operated in multishot mode, is well suited for the study of the influence of different rail materials on velocity and electrical contact of the armature and/or the wear of different rail materials. That is why we performed experiments with RAFIRA operated in multishot mode (firing rate of 50 Hz), using different rail materials (CuCr and Dural) and various shot energies. For these experiments, the shot energy for RAFIRA was raised, for the first time, up to the maximum energy at a disposal of 1.45 MJ per shot with projectile masses of over 120 g. In this way, we were able to show that the influence of the rail material depends on the applied shot energy: for low shot energies (<1 MJ), CuCr rails show better results in terms of velocities and exit times of the projectiles. This effect vanishes for high shot energies (>1 MJ). Whereas in terms of electrical contact, Dural rails show both less erosion and the capability to maintain a solid sliding contact until shot out for all energies applied.

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