Negative Hall coefficient of ultrathin niobium in Si/Nb/Si trilayers

I Zaytseva (1) , O Abal 'Oshev (1) , P Dłuzewski (1) , W Paszkowicz (1) , L.Y. L.Y. Zhu (2) , C.L. Chien (2) , M. Konczykowski (3) , Marta Z. Cieplak (1)

1 Institute of Physics
2 Department of Physics and Astronomy [Baltimore]
3 LSI - Laboratoire des Solides Irradiés

Structural and transport properties of thin Nb layers in Si/Nb/Si trilayers with Nb layer thickness d from 1.1 nm to 50 nm have been studied. With decreasing thickness, the structure of the Nb layer changes from polycrystalline to amorphous at d 3.3 nm, while the superconducting temperature T c monotonically decreases. The Hall coefficient varies with d systematically but changes sign into negative in ultrathin films with d < 1.6 nm. The influence of boundary scattering on the relaxation rate of carriers, and band broadening in the amorphous films, may contribute to this effect.

Domains: Physics [physics]; Condensed Matter [cond-mat]; Superconductivity [cond-mat.supr-con]

I Zaytseva, O Abal 'Oshev, P Dłuzewski, W Paszkowicz, L.Y. L.Y. Zhu, et al.. Negative Hall coefficient of ultrathin niobium in Si/Nb/Si trilayers. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2014, 90, pp.5. ⟨10.1103/PhysRevB.90.060505⟩. ⟨hal-01074691⟩