Conductivity of an atomically defined metallic interface

Oliver, David J.; Maassen, Jesse; Ouali, Mehdi El; Paul, William; Hagedorn, Till; Miyahara, Yoichi; Qi, Yue; Guo, Hong; Grütter, Peter

doi:10.1073/pnas.1208699109

Cited by 27 publications

(25 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have previously investigated the conductance loss due to interfaces between dissimilar metals, showing that the conductance across a W(111)/Au(111) boundary is diminished by a factor of 4× due to back-reflection at the interface due to the poor overlap of Bloch states [23]. Ballistic transmission losses at interfaces and grain boundaries have been investigated in relatively few experiments [28].…”

Section: Conductance Dropmentioning

confidence: 99%

Transient adhesion and conductance phenomena in initial nanoscale mechanical contacts between dissimilar metals

Paul¹,

Oliver²,

Miyahara³

et al. 2013

Nanotechnology

Self Cite

View full text Add to dashboard Cite

We report on transient adhesion and conductance phenomena associated with tip wetting in mechanical contacts produced by the indentation of a clean W(111) tip into a Au(111) surface. A combination of atomic force microscopy and scanning tunneling microscopy was used to carry out indentation and to image residual impressions in ultra-high vacuum. The ∼7 nm radii tips used in these experiments were prepared and characterized by field ion microscopy in the same instrument. The very first indentations of the tungsten tips show larger conductance and pull-off adhesive forces than subsequent indentations. After ∼30 indentations to a depth of ∼1.7 nm, the maximum conductance and adhesion forces reach steady state values approximately 12 × and 6 × smaller than their initial value. Indentation of W(111) tips into Cu(100) was also performed to investigate the universality of tip wetting phenomena with a different substrate. We propose a model from contact mechanics considerations which quantitatively reproduces the observed decay rate of the conductance and adhesion drops with a 1/e decay constant of 9-14 indentation cycles. The results show that the surface composition of an indenting tip plays an important role in defining the mechanical and electrical properties of indentation contacts.

show abstract

Section: Conductance Dropmentioning

confidence: 99%

Transient adhesion and conductance phenomena in initial nanoscale mechanical contacts between dissimilar metals

Paul¹,

Oliver²,

Miyahara³

et al. 2013

Nanotechnology

Self Cite

View full text Add to dashboard Cite

show abstract

“…[11][12][13][14] Therefore, beside confining the dimension of systems, introducing or removing of defects and boundaries can be considered as an alternative method to tailor the lattice thermal conductivity of crystalline materials. 12,15,16 Hence, it is crucial to explore and quantify the phonon scattering across crystalline boundaries. In the early 1950s, using dislocation theory and modeling the grain boundary as an array of dislocation, some analytical models for phonon scattering at low angle grain boundaries have been proposed.…”

mentioning

confidence: 99%

Impact of internal crystalline boundaries on lattice thermal conductivity: Importance of boundary structure and spacing

Aghababaei

Anciaux

Molinari

2014

Applied Physics Letters

View full text Add to dashboard Cite

The low thermal conductivity of nano-crystalline materials is commonly explained via diffusive scattering of phonons by internal boundaries. In this study, we have quantitatively studied phonon-crystalline boundaries scattering and its effect on the overall lattice thermal conductivity of crystalline bodies. Various types of crystalline boundaries such as stacking faults, twins, and grain boundaries have been considered in FCC crystalline structures. Accordingly, the specularity coefficient has been determined for different boundaries as the probability of the specular scattering across boundaries. Our results show that in the presence of internal boundaries, the lattice thermal conductivity can be characterized by two parameters: (1) boundary spacing and (2) boundary excess free volume. We show that the inverse of the lattice thermal conductivity depends linearly on a non-dimensional quantity which is the ratio of boundary excess free volume over boundary spacing. This shows that phonon scattering across crystalline boundaries is mainly a geometrically favorable process rather than an energetic one. Using the kinetic theory of phonon transport, we present a simple analytical model which can be used to evaluate the lattice thermal conductivity of nano-crystalline materials where the ratio can be considered as an average density of excess free volume. While this study is focused on FCC crystalline materials, where inter-atomic potentials and corresponding defect structures have been well studied in the past, the results would be quantitatively applicable for semiconductors in which heat transport is mainly due to phonon transport.

show abstract

“…The atomic orbital properties of the material can play a surprising role in basic research. A striking example is the experimental and modeling work of Oliver et al., where ballistic conduction across a gold/tungsten interface is drastically reduced because of the fundamental symmetry mismatch between the s‐wave‐like electron modes in Au and the d‐wave‐like modes in W. There are also many other situations where orbital symmetry at the s, p, and d levels is somehow important for the transport outcome, including the giant magnetoresistance of ZαGNR, spin–orbit effects in MoS 2 , and WSe 2 . Furthermore, at a practical level of developing potential applications, materials with f electrons are already valuable.…”

Section: Resultsmentioning

confidence: 99%

Electronic Transport Inhibiting of Carbon Nanotubes by 5f Elements

Jia

Gong

et al. 2020

Advcd Theory and Sims

View full text Add to dashboard Cite

Based on the combination of the non‐equilibrium Green's function and density functional theory, a theoretical method for studying the transport behavior of high angular momentum 5f electrons is developed and the transport properties of the structure for actinide atoms embedded in carbon nanotubes (An@CNTs, An = Ac, Th, Pa and U) is reported. Results show that An@CNTs have lower transmission coefficients than that of CNTs. Furthermore, electrical bias to the U@(4, 4)/(5, 5) CNTs induces an additional transition spectral peak, which demonstrates that the U@(4, 4)/(5, 5) CNTs has a lower resistance. Therefore, 5f electrons of actinide atoms inhibit the electronic transport of CNTs. These findings may provide fresh insight into the transport properties of systems having higher angular momentum electrons.

show abstract

Conductivity of an atomically defined metallic interface

Cited by 27 publications

References 38 publications

Transient adhesion and conductance phenomena in initial nanoscale mechanical contacts between dissimilar metals

Transient adhesion and conductance phenomena in initial nanoscale mechanical contacts between dissimilar metals

Impact of internal crystalline boundaries on lattice thermal conductivity: Importance of boundary structure and spacing

Electronic Transport Inhibiting of Carbon Nanotubes by 5f Elements

Contact Info

Product

Resources

About