Niobium for Superconductors

H.C. Starck supplies niobium (Nb) and tantalum (Ta) sheet and rod for low temperature superconductor (LTS) wire manufacturing requiring cryogenic cooling. We provide extrusion services for extruding large diameter wire bundles for final redrawing by the customer.

Niobium and tantlaum materials have unique properties that make them the primary choice materials for superconducting applications:

  • MRI and NMR medical equipment
  • Magnetic levitation
  • Mass spectroscopy
  • Particle accelerators
  • Nuclear fusion research equipment

H.C. Starck‘s niobium and tantalum rod and sheet are applied in large-scale scientific projects to create clean fusion energy as well as large, powerful particle accelerator experiments where a ring of superconducting magnets are used to boost the energy of the particles along a set collision path of accelerating structures.

Unique Properties for Manufacturing Superconductor Products

In the manufacturing of superconducting wire, both the sheet which is typically used as diffusion barrier between copper (Cu) and tin (Sn) and the rods which is mainly used to generate the Nb3Sn superconducting compound have strictly controlled mechanical properties, surface roughness and chemical composition. This is necessary in order to facilitate processing and ensure the realization of a high quality superconductor wire.

The main role of tantalum in superconductors is to form a stable and reliable diffusion barrier between the Cu matrix and Sn. This barrier starts as a sheet of Ta whose thickness will be reduced through the entire process of drawing to only a fraction of its initial thickness. It is paramount that the Ta layer remains intact preventing a direct contact between Cu and Sn. This is why the initial thickness uniformity, surface quality, microstructure and mechanical properties are of vital importance. Poor control of these properties can result in reduced yields, poor magnetic properties, and a number of other undesirable effects.

Nb properties are equally important for slightly different reasons and this is where H.C. Starck excels. Not only have we achieved processes allowing us tight control of all critical parameters and properties, but also H.C. Starck constantly strives to make improvements using microstructural or mechanical properties optimization capabilities at our in-house state-of-the-art Research and Development facilities.

LTS superconducting materials niobium and tantalum will continue to be used for the large particle accelerator programs.



  • Sizes Available:
    • Diameters: 10 – 100 mm
    • Max. length: 2.5 – 7.5 m
  • Microstructural control
  • In compliance with ASTM B392 (Nb) and B365 (Ta)
  • Consistent chemistry and mechanical properties



  • Sizes Available:
    • Sheet: 0.25 – 2.5 mm thick, up to 1m wide
    • Other dimensions available upon request
  • Excellent surface quality
  • In compliance with ASTM B393 (Nb) and B708 (Ta)
  • Consistent chemistry
  • Mechanical properties tuned to customer needs