| title: | Disorder and dynamics of conduction electrons in compounds with Ti5Te4 type structure |
|---|---|
| reg no: | ETF6655 |
| project type: | Estonian Science Foundation research grant |
| subject: |
1.3. Physics |
| status: | accepted |
| institution: | Institute of Physics at University of Tartu |
| head of project: | Andres Stolovitš |
| duration: | 01.01.2006 - 31.12.2009 |
| description: | Electron transport properties of compounds with quasi-one-dimensional crystal structure will be studied at temperatures 0.3–270 K and in the magnetic fields up to 12 T. The measurements will be carried out in three-dimensional (in the sense of weak localization) bulk single- and polycrystalline Mo5As4, Nb5-xTe4 (x~0.2), Ti5Te4, and Zr5Te4. The quantum interference contribution to the resistance and the electron dephasing times will be determined from the magnetoresistance and the temperature dependence of resistivity. We concentrate on the mechanisms of the electron-phonon scattering and the saturation of the dephasing time in the limit of low temperatures. The validity of the scaling relation of the dephasing time saturation value with the diffusion constant, which has been found for three-dimensional polycrystalline alloys, will be checked for compounds with Ti5Te4 structure-type. The electron-phonon scattering times as a function of temperature and an electron mean free path will be measured with the weak localization and the electron heating technique. The effect of structural defects on the electron-phonon interaction is expected to be observed in both single-and polycrystalline materials. Results will be compared with various theories of electron-phonon scattering. In the frame of this project the origin of the resistivity maximum around 30 K in Nb5-xTe4 will be investigated. Additional experiments show whether this behavior manifests the interference effects (interplay of the weak localization and the weak antilocalization) or a possible phase transition. |
| project group | ||||
|---|---|---|---|---|
| no | name | institution | position | |
| 1. | Tea Avarmaa | |||
| 2. | Raivo Jaaniso | |||
| 3. | Andres Stolovitš | Tartu Ülikooli Füüsika Instituut | ||
| 4. | Aleksei Šerman | |||