Theoretical analysis of the conductance histograms and structural properties of Ag, Pt, and Ni nanocontacts

F. Pauly, M. Dreher, J. K. Viljas, M. Häfner, J. C. Cuevas, and P. Nielaba
Phys. Rev. B 74, 235106 – Published 8 December 2006

Abstract

Conductance histograms are a valuable tool to study the intrinsic conduction properties of metallic atomic-sized contacts. These histograms show a peak structure, which is characteristic of the type of metal under investigation. Despite the enormous progress in the understanding of the electronic transport in metallic nanowires, the origin of this peak structure is still a basic open problem. In the present work we tackle this issue, extending our theoretical analysis of Au conductance histograms [Dreher et al., Phys. Rev. B 72, 075435 (2005)] to different types of metals, namely, Ag, Pt and ferromagnetic Ni. We combine classical molecular dynamics simulations of the breaking of nanocontacts with conductance calculations based on a tight-binding model. This combination gives us access to crucial information such as contact geometries, strain forces, minimum cross-sections, the conductance, transmissions of the individual conduction channels, and, in the case of Ni, the spin polarization of the current. We shall also briefly discuss investigations of Al atomic-sized contacts. From our analysis we conclude that the differences in the histograms of these metals are due to (i) the very different electronic structures, which means different atomic orbitals contributing to the transport and (ii) the different mechanical properties, which in a case such as Pt lead to the formation of special structures, namely, monoatomic chains. Of particular interest are results for Ni that indicate the absence of any conductance quantization, and show how the current polarization evolves (including large fluctuations) from negative values in thick contacts to even positive values in the tunneling regime after rupture of the contact. Finally, we also present a detailed analysis of the breaking forces of these metallic contacts, which are compared to the forces predicted from bulk considerations.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
12 More
  • Received 4 July 2006

DOI:https://doi.org/10.1103/PhysRevB.74.235106

©2006 American Physical Society

Authors & Affiliations

F. Pauly1,2,*, M. Dreher3, J. K. Viljas1,2, M. Häfner1,2, J. C. Cuevas1,2,4, and P. Nielaba3

  • 1Institut für Theoretische Festkörperphysik, Universität Karlsruhe, D-76128 Karlsruhe, Germany
  • 2Forschungszentrum Karlsruhe, Institut für Nanotechnologie, D-76021 Karlsruhe, Germany
  • 3Fachbereich Physik, Universität Konstanz, D-78457 Konstanz, Germany
  • 4Departamento de Física Teórica de la Materia Condensada C-V, Universidad Autónoma de Madrid, E-28049 Madrid, Spain

  • *Electronic address: Fabian.Pauly@tfp.uni-karlsruhe.de

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 74, Iss. 23 — 15 December 2006

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×