High-Entropy Alloy Superconductivity

High-entropy alloys (HEAs) have emerged as a distinctive class of materials in which five or more principal elements occupy a simple crystallographic lattice in near-equimolar proportions, yielding exceptionally high configurational entropy. When such alloys exhibit superconductivity, they combine remarkable structural disorder with zero-resistance electrical transport. Since the first demonstration of superconductivity in a body-centred-cubic HEA in 2014, research has revealed that these materials can sustain coherent Cooper pairing despite strong atomic-scale randomness. HEA superconductors often display enhanced mechanical hardness, tolerance to irradiation, and stability under extreme pressure, setting them apart from conventional elemental or binary superconductors. Their robustness and tunable critical temperatures make them attractive for applications ranging from high-field magnets and superconducting wires to devices in aerospace and nuclear fusion environments. Ongoing investigations aim to elucidate the interplay between mixing entropy, lattice dynamics and electron-phonon coupling, with the goal of designing HEAs that combine high critical current densities, large upper critical fields and operational resilience in harsh conditions.

Research from Nature Portfolio

Recent studies have demonstrated that high-quality HEA thin films of Ta–Nb–Hf–Zr–Ti prepared by pulsed laser deposition exhibit critical current densities exceeding 1 MA cm⁻² at 4.2 K and maintain superconductivity after heavy-ion irradiation, indicating exceptional tolerance to displacement damage. Investigations under high pressure of an HEA-type telluride (AgInSnPbBiTe₅) with CsCl-type structure have shown that its transition temperature remains essentially constant from 13 to 35 GPa, suggesting a universal pressure-insensitive superconducting state linked to high configurational entropy. Furthermore, the incorporation of an actinide element in an f-electron HEA, [TaNb]₀.₃₁(TiUHf)₀.₆₉, has expanded the compositional landscape, revealing phonon-mediated superconductivity at approximately 3.2 K on a body-centred-cubic lattice with a upper critical field above 6 T.

High-Entropy Alloy Superconductivity publication trend

The graph below shows the total number of articles in high-entropy alloy superconductivity across all publications each year (not limited to Nature Index journals).

Technical terms

High-Entropy Alloy (HEA): An alloy composed of five or more principal elements in near-equimolar ratios, resulting in high configurational entropy and often simple lattice structures.

Superconductivity: A quantum phenomenon in which a material conducts electric current without resistance below a characteristic critical temperature (Tc).

Configurational Entropy: A measure of the number of ways elements can be arranged on lattice sites, which stabilises disordered solid solutions in HEAs.

Critical Current Density (Jc): The maximum electrical current per unit area a superconductor can carry without losing the superconducting state.

Electron-Phonon Coupling: The interaction between electrons and lattice vibrations that can mediate the formation of Cooper pairs in conventional superconductors.

References

1. Glassy atomic vibrations and blurry electronic structures created by local structural disorders in high-entropy metal telluride superconductors. Materials Today Physics (2023).
2. New high-entropy alloy superconductor Hf21Nb25Ti15V15Zr24. Results in Physics (2019).
3. Superconductivity in CuAl2-type Co0.2Ni0.1Cu0.1Rh0.3Ir0.3Zr2 with a high-entropy-alloy transition metal site. Materials Research Letters (2020).
4. High critical current density and high-tolerance superconductivity in high-entropy alloy thin films. Nature Communications (2022).
5. Superconductivity in a uranium containing high entropy alloy. Scientific Reports (2020).
6. Robustness of superconductivity to external pressure in high-entropy-alloy-type metal telluride AgInSnPbBiTe5. Scientific Reports (2022).