| 1. |
|
|
| 2. |
- Brauer, H.E., et al.
(författare)
-
Na intercalation of VSe2 studied by photoemission and scanning tunneling microscopy
- 1997
-
Ingår i: Physical Review B Condensed Matter. - 0163-1829 .- 1095-3795. ; 55:15, s. 10022-10026
-
Tidskriftsartikel (refereegranskat)abstract
- In situ Na intercalation of the layered compound VSe2 has been studied with photoemission and scanning tunneling microscopy. Core-level spectroscopy proves that Na deposited in UHV onto the VSe2 surface rapidly intercalates, leaving only small amounts at the surface. The scanning tunneling microscopy measurements show that the intercalated Na is not uniformly distributed between the VSe2 layers, but preferentially in two-dimensional islands. Thus the surface region is divided into intercalated and nonintercalated areas. Hole-like features in the intercalated areas are interpreted as locally missing Na.
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Costa-Kramer, J.L., et al.
(författare)
-
Conductance quantization histograms of gold nanowires at 4 K
- 1997
-
Ingår i: Physical Review B Condensed Matter. - 0163-1829 .- 1095-3795. ; 55:19, s. 12910-12913
-
Tidskriftsartikel (refereegranskat)abstract
- Driving a scanning tunneling microscope (STM) tip into a metallic surface and pulling it out afterwards results in the formation of a nanometer-sized wire (nanowire) between the electrodes. The electrical conduction measured during this process shows signs of quantized conductance in units of G0=2e2/h. Due to the inherent irreproducibility of the measured conductance curves, the standard technique has been to construct histograms with a few hundred selected curves. These histograms, for gold nanowires at room temperature, have shown three to four peaks at integer values of 2e2/h, while in a low-temperature mechanically controlled break junction study, with statistics using only 65 curves, only the first peak has been reported. A proposed explanation for this apparent experimental discrepancy has been a higher nanowire temperature arising from the higher retraction speed used in scanning tunneling microscopy measurements. However, our simple estimation using macroscopic heat transport theory produces a very low temperature rise, less than 1 μK. In this work, an improved statistical study is presented, where histograms built with thousands of consecutive gold contact breakage experiments at 4 K show up to seven conductance peaks. Thus, no significant differences with our previous room-temperature (RT) studies are observed, pointing to a conductance quantization behavior that is the same at low, intermediate, and high (RT) temperatures.
|
|
| 6. |
- Costa-kramer, J.L., et al.
(författare)
-
Conductance quantization in bismuth nanowires at 4 K
- 1997
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 78:26, s. 4990-4993
-
Tidskriftsartikel (refereegranskat)abstract
- Conductance experiments on Bi nanowires at 4 K, obtained with a scanning tunneling microscope, are presented. The conductance of these Bi nanocontacts, formed between two Bi electrodes, exhibits plateaus at quantized values of G0 = 2e2/h, remaining basically constant during electrode separations of about 50 nm. This is the first time that such plateaus have been observed in semimetals. The histogram of conductance values, constructed with thousands of consecutive contact breakage conductance experiments, exhibits clear peaks at G0 and 2G0.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
|
|
