Dresden 2006 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
CPP: Chemische Physik und Polymerphysik
CPP 16: Electronic Structure and Spectroscopy II
CPP 16.3: Vortrag
Mittwoch, 29. März 2006, 14:30–14:45, ZEU 160
ESR-Imaging including Conduction Electron Drift Velocity Measurement — •Malte Drescher1, Noam Kaplan2, and Elmar Dormann1 — 1Physikalisches Institut, Universität Karlsruhe(TH), D-76128 Karlsruhe, Germany — 2Racah Institute of Physics, Hebrew University, Jerusalem, Israel
This contribution presents the results on ESR-imaging via temperature dependent pulsed X-band ESR focussing on quasi one-dimensional organic conductors, where due to their long T2-time constants even pulsed conduction electron spin resonance and a resolution better than 10µ m is possible.
Additionally to depicting spin densities we succeeded in spatially resolved determining dynamic properties, e.g. spin-spin-, spin-lattice-relaxation, spin diffusion coefficient or phase transition temperatures.
Since flow measurement is an established tool in NMR-imaging, the possibility of performing ESR experiments on conduction electrons allows in principle to determine the electron spin drift velocity for given electrical current. An appropriate pulsed gradient and current ESR detection scheme was developed and the first successful experiment of detecting the phase shift in the ESR-signal induced by an applied electrical current was performed. The ohmic correlation is demonstrated in a range of more than +/- 250mA in crystals exhibiting a cross-sectional area of less than 1mm2 and a maximum drift velocity of 0.3 m/s was found in the metallic phase of a radical cation salt.