Highly aligned carbon nanotube forests coated by superconducting NbC

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Composite materials offer enhanced functionalities beyond individual components.
• Superconductors like niobium carbide (NbC) have critical properties influenced by their structure.
• Carbon nanotubes (CNTs) possess unique microstructural and electrical characteristics.

Purpose of the Study:

• To investigate the effect of coating carbon nanotube forests with niobium carbide (NbC).
• To evaluate the impact on the microstructure of carbon nanotubes and the superconducting properties of NbC.
• To determine if CNTs can enhance the performance of NbC superconductors.

Main Methods:

• Coating of carbon nanotube forests with superconducting niobium carbide (NbC).
• Microstructural analysis of the resulting composite material.
• Measurement of superconducting properties, including irreversibility and upper critical field.

Main Results:

• Coating CNTs with NbC did not disrupt the nanotube microstructure.
• NbC exhibited significantly improved superconducting properties, including higher irreversibility and upper critical field.
• An upper critical field of ~5 T at 4.2 K was achieved, exceeding the 1.7 T for pure bulk NbC.
• Aligned CNTs induced anisotropy in the upper critical field, with higher values when the magnetic field was parallel to the CNT growth direction.

Conclusions:

• Highly oriented carbon nanotubes embedded in a superconducting NbC matrix enhance NbC's superconducting properties.
• CNTs act as effective defects within the NbC matrix, improving its performance.
• This composite material demonstrates potential for advanced superconducting applications.