A collaborative research team led by Prof. MA Yanwei from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences has set a new global performance record for iron-based superconducting wires.

Their breakthrough, achieved by engineering high-density flux pinning centers through an asymmetric stress field strategy, is published in Advanced Materials.

The Steady High Magnetic Field Facility (CHMFL) at the Hefei Institutes of Physical Science played a pivotal role in this achievement, with its water-cooled magnet WM5 providing critical experimental support for validating the wires.

Iron-based superconductors are considered essential for next-generation high-field technologies, including particle accelerators, fusion devices, and magnetic resonance imaging systems. These materials offer high critical fields, low anisotropy, and cost-effectiveness. However, their brittle lattices pose a significant challenge in introducing the dense flux pinning centers necessary for carrying large lossless currents.

In this study, the researchers developed an innovative approach based on asymmetric stress fields. Through a scalable extrusion technique, they achieved synergistic control of hydrostatic pressure and shear stress, inducing localized lattice slip and twisting in the rigid crystal structure. This process produced a high density of dislocations, which were further optimized through heat treatment to form ordered arrays – creating an efficient network of flux pinning centers.

The results are remarkable. The critical current density (Jc) of the engineered wires increased sharply. At 10 tesla (T), Jc rose from 1.5×10⁵ A/cm² to 4.5×10⁵ A/cm², while at 30 T it reached 2.1×10⁵ A/cm²—five times higher than previous benchmarks—establishing a new global record for iron-based superconducting wires.

"Testing these high-performance wires required magnetic fields above 30 T, which was made possible by CHMFL," said Prof. MA. "Its WM5 water-cooled magnet provided the crucial experimental environment to verify the wires' current-carrying capabilities under such extreme conditions, ensuring the reliability of the breakthrough."

This study paves a new, low-cost path for developing high-performance iron-based superconducting wires, accelerating their practical application in cutting-edge, high-field technologies.

Transport current test under high magnetic fields of 25–33 T (Image by JIANG Donghui)