Santiago Herrera
Project Year
Santiago

Superconducting materials are described by their zero electrical resistance and magnetic flux expulsion below a critical temperature, Tc. These properties make superconductors invaluable for applications requiring highly efficient power transmission, strong electromagnets, and advanced quantum technologies. New superconducting material discoveries are often driven by structural changes of previously known materials. While ɑ–Vanadium belongs to the 229-space group, in this study we propose the discovery of a new elemental β–Vanadium superconducting structure in the A15 structure group with a significantly higher Tc. This new form of elemental V was found after annealing single-crystal ZrV2 at high temperatures under low oxygen conditions. Both ɑ and β Vanadium phases exhibit structural similarities with Tungsten, a well-known analogous superconductor, the β form of Tungsten demonstrates markedly different physical properties to its ɑ counterpart, and both phases share the same space groups as their Vanadium analogues. In this case, we propose the formation of this beta-V phase through oxygen pumping out the zirconium from the vanadium pyrochlore lattice. Magnetization measurements on the resulting samples show a sharp superconducting transition at 16 K, significantly higher than the 5.4 K typically observed in ɑ–V. Analysis via powder X-ray diffraction and scanning electron microscopy indicates the formation of a distinct V-rich phase and the migration of Zr out of the ZrV2 matrix. These findings point towards the discovery of a previously unknown V phase with enhanced electronic properties. The discovery of β–Vanadium in the A15 structure expands the catalog of elemental superconductors and may represent the highest Tc observed at atmospheric pressure in any elemental superconductor to date.

Major
Physics
University
University of California, Santa Barbara
Faculty Sponsor(s):
Stephen Wilson
Departments:
Materials
Mentor(s):
Sarah Schwarz