| 1. |
|
|
| 2. |
- Tatte, T, et al.
(författare)
-
Transparent and conductive Sb-doped tin oxide SPM tips prepared by sol-gel method
- 2002
-
Ingår i: Materials Science and Engineering C: Materials for Biological Applications. - 0928-4931. ; 19:1-2, s. 101-104
-
Tidskriftsartikel (refereegranskat)abstract
- The rapid progress in scanning probe microscopy (SPM) techniques in the last decade has induced an increasing need for manufacturing advanced SPM tips. One important case is conductive and transparent tips. For such tips, only a few techniques have been proposed. which are either expensive or have poor reproducibility. We here propose a simple and cheap sol-gel technique to prepare fibers with a suitably sharp apex so that they can be used as SPM tips. The fibers were spinned off from a high-viscosity solution of tin alkoxide and SbCl3 hydrolysed in hurnid air and baked at 520 degreesC for several hours. The radii of the resulting tips were estimated by transmission electron microscopy to be less than 50 am. The resistivity of the transparent fibers was measured using different Sb-doping (0.5-1 wt.%) of the tin oxide, The temperature dependence of the conductivity and light absorption were investigated down to liquid He temperatures.
|
|
| 3. |
- Erts, D, et al.
(författare)
-
Instrumentation of STM and AFM combined with transmission electron microscope
- 2001
-
Ingår i: Applied Physics A. - : Springer Science and Business Media LLC. - 0947-8396 .- 1432-0630. ; 72:7, s. 71-74
-
Tidskriftsartikel (refereegranskat)abstract
- A scanning tunneling microscope (STM) combined with a transmission electron microscope (TEM) is a powerful tool for direct investigation of structures, electronic properties, and interactions at the atomic scale. Here, we report on two different designs of such TEM-STM as well as an extension with an atomic force microscope (TEM-AFM). In the first TEM-STM design, a stepper motor, combined with a one-dimensional inertial slider, was used to perform the coarse approach. The advantage of this design was the strong pulling force that enabled notched metallic wires to be broken inside the TEM, which lead to clean sample surfaces. A second design, with a three-dimensional inertial slider, allowed lateral motion inside the TEM, which simplified the adjustment of tip location on the sample. By replacing the STM tip with a standard AFM-cantilever chip, a new combination was demonstrated: TEM-AFM. Here the force was simply measured by direct TEM imaging of the motion of the AFM tip. Some experimental results are included to illustrate the capabilities of TEM-STM and TEM-AFM.
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Pokropivny, A.V., et al.
(författare)
-
Study of Nanoscale Contacts with the Help of Combined TEM-AFM Technique and Theoretical MD-TM Calculations: In situ Transformations of Gold Nanowires
- 2004
-
Ingår i: Physics of low-Dimensional structures. - 0204-3467. ; 1-2, s. 83-90
-
Tidskriftsartikel (refereegranskat)abstract
- Nanoscale gold contacts were investigated both experimentally and theoretically. Simulations of in situ processes in a new combined TEM-AFM microscope were performed by molecular dynamics and theoretical mechanics methods. Atomistic transformations of gold nanometer-sized wires (nanowires) between Au-probe and Au-surface were studied in processes both of loading-unloading and in the normal, lateral, diagonal and zigzag directions of the probe motion. Molecular dynamics was used for studies of "adhesion avalanche", shear and strain deformations. Theoretical mechanics was used for studies of jump-to-contact and jump-off-contact phenomena. Reorientations from (100) to (111) planes with formation of extended zigzag, vacancy cavities, a double-neck creation and a slip along the (110) plane with formation of twins and steps were observed. Deformation mechanisms were shown to depend on schemes of motions and on the ratio between the relative velocity of the probe and surface motion and the velocity of the defect relaxation.
|
|
| 8. |
- Tatte, T, et al.
(författare)
-
Metal oxide based SPM tips prepared by sol-gel method
- 2002
-
Ingår i: Physics of Low-Dimensional Structures. - 0204-3467. ; 5-6, s. 31-37
-
Tidskriftsartikel (refereegranskat)abstract
- Up to date SNOM tips have. been prepared from SiO2 based materials using etching or locally melt fibre's stretching for tip sharpening [1,2] Usage of other metal oxides has been restricted because of the lack Of methods for obtaining the tips with suitable geometrical configuration. In our previous work we have proposed the technique for preparing transparent and electroconductive SnO2 fibres and tips by sol-gel method [3]. In the present investigation we have demonstrated that the sol-gel method provides the wide range of metal oxides to obtain SPM fibre tips. The new method of preparation enables to study tips based on oxide or oxide mixtures to create sensors with new properties for different applications. We propose some methods for preparing suitable precursors for spinning of pure and mixed TiO2, SnO2, SiO2 fibres. In those new methods the sharpening of tips is achieved in fibre drawing procedure. That is carried out at room temperature in humid atmosphere and then fibres are baked at 300-700degreesC for crystallisation of the material.
|
|
| 9. |
- Andzane, J., et al.
(författare)
-
Application of Tuning Fork Sensors for In-situ Studies of Dynamic Force Interactions Inside Scanning and Transmission Electron Microscopes
- 2012
-
Ingår i: Medziagotyra. - : Kaunas University of Technology (KTU). - 1392-1320. ; 18:2, s. 197-201
-
Tidskriftsartikel (refereegranskat)abstract
- Mechanical properties of nanoscale contacts have been probed in-situ by specially developed force sensor based on a quartz tuning fork resonator (TF). Additional control is provided by observation of process in scanning electron microscope (SEM) and transmission electron microscope (TEM). A piezoelectric manipulator allows precise positioning of atomic force microscope (AFM) probe in contact with another electrode and recording of the IF oscillation amplitude and phase while simultaneously visualizing the contact area in electron microscope. Electrostatic control of interaction between the electrodes is demonstrated during observation of the experiment in SEM. In the TEM system the TF sensor operated in shear force mode: Use of TEM allowed for direct control of separation between electrodes. New opportunities for in situ studies of nanomechanical systems using these instruments are discussed.
|
|
| 10. |
- Finér, L., et al.
(författare)
-
Variation in fine root biomass of three European tree species : Beech (Fagus sylvatica L.), Norway spruce (Picea abies L. Karst.) and Scots pine (Pinus sylvestris L.)
- 2007
-
Ingår i: Plant Biosystems. - : Informa UK Limited. - 1126-3504 .- 1724-5575. ; 141:3, s. 394-405
-
Tidskriftsartikel (refereegranskat)abstract
- Fine roots (< 2 mm) are very dynamic and play a key role in forest ecosystem carbon and nutrient cycling and accumulation. We reviewed root biomass data of three main European tree species European beech, (Fagus sylvatica L.), Norway spruce (Picea abies L. Karst.) and Scots pine (Pinus sylvestris L.), in order to identify the differences between species, and within and between vegetation zones, and to show the relationships between root biomass and the climatic, site and stand factors. The collected literature consisted of data from 36 beech, 71 spruce and 43 pine stands. The mean fine root biomass of beech was 389 g m(-2), and that of spruce and pine 297 g m(-2) and 277 g m(-2), respectively. Data from pine stands supported the hypothesis that: root biomass is higher in the temperate than in the boreal zone. The results indicated that the root biomass of deciduous trees is higher than that of conifers. The correlations between root biomass and site fertility characteristics seemed to be species specific. There was no correlation between soil acidity and root biomass. Beech fine root. biomass decreased with stand age whereas pine root biomass increased with stand age. Fine root biomass at tree level. correlated better than stand level root biomass with stand characteristics. The results showed that there exists a strong relationship between the fine root biomass and the above-ground biomass.
|
|
