Quantitative tunneling spectroscopy of nanocrystals

doi:10.2172/1057556

Abstract

The proposed goals of this collaborative work were to systematically characterize the electronic structure and dynamics of 3-dimensional metal and semiconducting nanocrystals using scanning tunneling microscopy/spectroscopy (STM/STS) and ballistic electron emission spectroscopy (BEES). This report describes progress in the spectroscopic work and in the development of methods for creating and characterizing gold nanocrystals. During the grant period, substantial effort also was devoted to the development of epitaxial graphene (EG), a very promising materials system with outstanding potential for nanometer-scale ballistic and coherent devices ("graphene"Â refers to one atomic layer of graphitic, sp2 -bonded carbon atoms [or more loosely, few layers]). Funding from this DOE grant was critical for the initial development of epitaxial graphene for nanoelectronics

Tunneling spectroscopy study of YBa sub 2 Cu sub 3 O sub 7 thin films using a cryogenic scanning tunneling microscope

Wilkins, R. ; Amman, M. ; Soltis, R.E. ; ... May 1990

We have measured reproducible tunneling spectra on YBa{sub 2}Cu{sub 3}0{sub 7} thin films with a cryogenic scanning tunneling microscope. We find that the I-V curves are generally of three types. The most common type, featured in a large majority of the data, shows a region of high conductance at zero bias. The amplitude of this region is inversely proportional to the tunneling resistance between the tip and sample. It is possible that this can be explained in terms of Josephson effects with the films, although an alternative is given based on electronic self-energy corrections. Data showing capacitive charging steps aremore »« less
Surface structure and analysis with scanning tunneling microscopy and electron tunneling spectroscopy: Progress report, May 1, 1986-April 30, 1987

Coleman, R.V. January 1987

The discussion includes a list of publications, talks and theses, the design and fabrication of the microscope, charge-density wave studies with scanning tunneling microscopes at 77 and 4.23 K, and data acquisition and graphics display systems. 3 figs.
Surface structure and analysis with scanning tunneling microscopy and electron tunneling spectroscopy

Coleman, R.V. January 1990

During the current grant period we have continued to develop the spectroscopic applications of the Scanning Tunneling Microscopy and have carried out a large number of measurements on the gap structure due to charge-density waves and superconductivity. The measured energy gaps in 2H-TaSe{sub 2}, 2H-TaS{sub 2} and 2H-NbSe{sub 2} are {Delta} = 80, 50, and 34 mV giving values of 2{Delta}/k{sub B}T{sub c} of 15.2, 15.4 and 21.9. Measured energy gaps in 1T-TaSe{sub 2} and 1T- TaS{sub 2} are {Delta} {approx equal} 150 mV with 2{Delta}/k{sub B}T{sub c} {approx equal} 5.8. In the linear chain compounds, initial measurements have determinedmore »« less
Surface structure and analysis with scanning tunneling microscopy and electron tunneling spectroscopy

Coleman, R.V. January 1992

This report discusses the atomic force microscopy and correlation of charge-density-wave energy gaps and impurity pinning in NbSe{sub 3}. (LSP).
DOI: 10.2172/5879901

Full Text Available
Surface structure and analysis with scanning tunneling microscopy and electron tunneling spectroscopy

Coleman, R.V. January 1992

This report discusses the following topics: charge-density waves in layer structures; charge-density waves in linear chain compounds; spectroscopy with the STM; STM studies of oxides; and development of atomic force microscopy. (LSP).
DOI: 10.2172/6017304

Full Text Available

Title: Quantitative tunneling spectroscopy of nanocrystals

Abstract

Citation Formats

Tunneling spectroscopy study of YBa sub 2 Cu sub 3 O sub 7 thin films using a cryogenic scanning tunneling microscope

Surface structure and analysis with scanning tunneling microscopy and electron tunneling spectroscopy: Progress report, May 1, 1986-April 30, 1987

Surface structure and analysis with scanning tunneling microscopy and electron tunneling spectroscopy

Surface structure and analysis with scanning tunneling microscopy and electron tunneling spectroscopy

Surface structure and analysis with scanning tunneling microscopy and electron tunneling spectroscopy