Article

Journal of Superconductivity

, Volume 13, Issue 5, pp 855-861

First online:

Localized High-Tc Superconductivity on the Surface of Na-Doped WO3

  • S. ReichAffiliated withDepartment of Materials and Interfaces, The Weizmann Institute of Science
  • , G. LeitusAffiliated withDepartment of Materials and Interfaces, The Weizmann Institute of Science
  • , Y. TssabaAffiliated withDepartment of Materials and Interfaces, The Weizmann Institute of Science
  • , Y. LeviAffiliated withRacah Institute of Physics, The Hebrew University
  • , A. SharoniAffiliated withRacah Institute of Physics, The Hebrew University
  • , O. MilloAffiliated withRacah Institute of Physics, The Hebrew University

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

WO3 crystals were doped with Na on the surface to ∼7% nominal atomic concentration. Scanning tunneling microscopy and spectroscopy were employed, together with magnetization measurements, in the study of these crystals. Tunneling experiments reveal superconducting islands, 20–150 nm in size, covering about 10% of the surface, the rest of which is insulating. Magnetization measurements show that the superconducting phase formed at the surface has a critical temperature of 91 K, while tunneling spectroscopy yields superconducting gaps having values up to 2Δ/kT c ∼ 4. Presumably most of the sodium is concentrated in these islands and therefore they are metallic in nature, above 30% in atomic concentration. This material is therefore a noncuprate superconductor with a high critical temperature.

Na-doped WO3 high-T c superconductivity noncuprate superconductor