We report on the investigations of the structural and superconducting properties of Nb3Sn in the GPa range by angular dispersive synchrotron X-ray diffraction and ab-initio calculations based on density functional theory. X-ray Diffraction experiments were carried out on Nb3Sn technological samples to explore the equation of state at room temperature and at pressures up to 43.5 GPa: We observe an anomaly in the P-V curve in the region 5-10 GPa. The ab-initio calculated lattice parameter of Nb3Sn as a function of pressure has been used as an input for the calculation of the phonon dispersion curves and of the electronic band structures along different high-symmetry directions in the Brillouin zone. The critical temperature has been calculated as a function of the hydrostatic pressure by means of the Allen-Dynes modification of the McMillan formula: We found that its behavior is dictated mostly by the electronic contribution, but evident anomalies up to 6 GPa arise from phonons. These findings are a clue that Nb3Sn could have some structural instabilities with impact on its superconducting properties when subjected to a pressure of a few GPa and they represent an important step to understand and optimize the performances of Nb3Sn materials under the hard operational conditions of high field superconducting magnets.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
Loria, R., De Marzi, G., Anzellini, S., Muzzi, L., Pompeo, N., Gala, F., ... Meneghini, C. (2017). The Effect of Hydrostatic Pressure on the Superconducting and Structural Properties of Nb. IEEE Transactions on Applied Superconductivity, 27(4), -. . https://doi.org/10.1109/TASC.2016.2642398