Microstructure and Superconductivity of Mechanically Alloyed Nb_0.67(TiZrHf)_0.33 High-Entropy Alloy

Area of Science:

• Materials Science
• Condensed Matter Physics
• Superconductivity

Background:

• High-entropy alloys (HEAs) are advanced materials with unique properties due to their complex compositions.
• Superconducting HEAs are of interest for potential applications in electronics and energy.

Purpose of the Study:

• To synthesize a superconducting HEA powder using mechanical alloying for the first time.
• To investigate the structural and superconducting properties of the Nb0.67(TiZrHf)0.33 alloy.

Main Methods:

• Mechanical alloying for powder synthesis.
• X-ray diffraction (XRD) for structural analysis.
• Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) for composition and morphology.
• Magnetic measurements and specific heat analysis for superconductivity characterization.

Main Results:

• Successful synthesis of Nb0.67(TiZrHf)0.33 HEA powder in a single-phase body-centered cubic structure.
• Confirmation of bulk superconductivity with a critical temperature (Tc) between 6-7.5 K.
• Determination of an upper critical field (μ0Hc2) in the range of 6.4-7.6 T.
• Observed broad superconducting transition due to chemical disorder, characteristic of HEAs.

Conclusions:

• Mechanical alloying is a viable method for producing superconducting HEA powders.
• The synthesized HEA powder is suitable for consolidation via sintering.
• This work provides a robust platform for studying superconductivity in highly disordered systems.