Dresden 2006 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 4: New Experimental Techniques
CPP 4.10: Vortrag
Montag, 27. März 2006, 16:45–17:00, ZEU Lich
3-d Cylindrical Pulsed X-Band ESR-Imaging — •Michael Glied1,2, Malte Drescher2, and Elmar Dormann2 — 1now at 1. Physikalisches Institut, Universität Stuttgart, D-70550 Stuttgart, Germany — 2Physikalisches Institut, Universität Karlsruhe (TH), D-76128 Karlsruhe, Germany
ESR-Imaging is a technique using similar principles to the established NMR-imaging; however, the fast electron spin relaxation time constants are an experimental challenge. Spin echo backprojection reconstruction imaging in the X-band using a static magnetic field gradient is the favourable application for material science where temperature variation in metal cryostat is necessary. Nevertheless, studying quasi-one dimensional organic conductors only a pulsed phase encoding gradient can be tolerated in the conduction direction in order to avoid imaging artefacts caused by electron spin diffusion.
We present an appropriate three dimensional imaging scheme, combining static gradient backprojection reconstruction and pulsed gradient fourier imaging to scan the reciprocal space in cylindrical coordinates and obtain three dimensional images of various physical parameters like spin density, relaxation time or defect concentration.
Conduction electron density images with a volume element size of 13 × 13 × 17µ m3 as well as images of the spin lattice relaxation time, obtained by inversion recovery, with a volume element size of 13 × 13 × 68µ m3 are presented for fluoranthene radical cation salt single crystals of typical sizes of 0.4 × 0.4 × 1mm3.