Magnetic flux jumps upon magnetization of superconducting niobium plate with the magnetic field oriented normally and parallel to the surface

The dependence of magnetization $M$ on magnetic field $H$ was measured for a thin superconducting niobium plate with strong magnetic flux pinning with the field oriented normally and parallel to the sample plane. At $T<T_c$, dependences $M(H)$ show a hysteretic behavior with a peak effect in large fields; the shape of the hysteresis loop depends on the field orientation. At temperatures below $\sim T_c/2$ magnetic field jumps appear on dependences $M(H)$, and their behavior also depends on the field orientation. When a good conductor is in the in a good thermal contact with the planar superconducting sample, the flux jumps are noticeably reduced in the perpendicular field orientation, while the flux jumps in the parallel orientation remain unchanged. The decrease in the magnitude of the flux jumps with a transverse orientation of the magnetic field occurs due to the electrodynamic braking of magnetic instability, which could lead to a magnetic flux jump.