We study interactions of perpendicular and longitudinal magnetic fields in niobium films of different thickness in a wide range of temperatures below the superconducting transition temperature $\left(T_C\right)$. In 100-nm Nb film at all temperatures the longitudinal field $H_{\left|\right|}$ practically does not influence the dynamics of the normal flux. However, in 200-nm Nb film, a considerable anisotropy in the vortex motion is found with advanced propagation of the normal flux along $H_{\left|\right|}$ at $T>T_C/2$ and the preferential jumpwise growth of the thermomagnetic flux dendrites across $H_{\left|\right|}$ at $T<T_C$. Appearance of the in-plane vortices and their cutting reconnection with tilted vortices induced by the normal field $H_{\perp }$ is the reason for the observed anisotropy in the thicker film. Absence of the in-plane vortices and much smaller tilt of vortices generated by $H_{\perp }$ explain the isotropic normal flux dynamics in the thinner film. Our results open an alternative way of manipulating both slow vortex motion and fast thermomagnetic avalanches.

• Received 26 August 2016
• Revised 4 October 2016

DOI:https://doi.org/10.1103/PhysRevB.94.184502