Flux pinning behavior in Nb50Ti/Cu superconducting composite with different form of artificial pinning center

Artificial pinning center (APC) niobium-titanium composites achieve very high critical current density value at low magnetic field (below 5 T), but they are inferior to conventional composites at high magnetic fields (above 7 T) due to weak flux pining force. Therefore, realization of flux pinning behavior and improvement of flux pinning force of NbTi composite are very important. In this paper, three forms of niobium APC were introduced into Nb50Ti/Cu composites, that is, island-shaped, net-shaped and sheet-shaped Nb APC. The results show that Nb50Ti/Cu composites with island-shaped APC have highest flux pinning force over other two kinds of composites with net-shaped and sheet-shaped APC, however, this difference will be reduced after heat treatment process