Effects of ordered structure on superconductivity in Ti70−xZr30Nbx (15≤ x ≤ 60)
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences Beijing 100190, PRC
2 School of Materials Science and Engineering, Beihang University - Beijing 100191, PRC
Accepted: 25 November 2011
Superconductivity and structural properties of Ti70−xZr30Nbx have been systematically investigated for x ranging from 0 to 60. Superconductivity is observed in the cubic β-phase with 10≤x≤ 60. Moreover, evident modifications in superconductivity and superstructure, being interpreted as Nb and Ti local orders, are discovered in samples with 25≤x≤ 50. This superstructure phase in general coexists with the cubic β-phase and yields two superconducting transitions in the superconducting materials. Electronic structure calculations reveal a relatively higher density of states for the superstructure phase at the Fermi level, therefore a strong electron-phonon coupling and higher superconducting Tc are expected in agreement with the experimental data.
PACS: 74.62.Bf – Effects of material synthesis, crystal structure, and chemical composition / 74.20.Pq – Electronic structure calculations / 61.05.J- – Electron diffraction and scattering
© EPLA, 2012