Electrical, magnetic and optical characterisation of donor-acceptor systems
| dc.contributor.advisor | Ashwell, G. J. | |
| dc.contributor.author | Martin, P. J. P. | |
| dc.date.accessioned | 2016-08-24T09:23:20Z | |
| dc.date.available | 2016-08-24T09:23:20Z | |
| dc.date.issued | 1991-07 | |
| dc.description.abstract | Three novel donor-acceptor systems have been characterised through their spectroscopic properties, magnetic susceptibility, conductivity and second harmonic generation. The magnetic properties of (H2DPE)xx+(DPE)^ x(TCNQ)gX and (H2DPA)xx+(DPA) 1 x(TCNQ)gX' where DPE = 1,2-di(4-pyridyl)ethylene, DPA = 1,2-di(4-pyridyl)ethane, TCNQ = tetracyanoquinodimethane and H2 signifies proton diquaternisation, have been found to depend upon the stoichiometry: For x > \ the magnetic susceptibility decreases with increasing x whereas for x ~ \ it is anomolously large, being ferromagnetically enhanced above the Curie Law value. A possible model involving spin dilution is proposed and its predictions are compared with the experimental results. Langmuir-Blodgett (LB) films of the long-chained analogues of the materials, (C^g)2DPE (TCNQ) 2 and (Cig^DPE^TCNQ)^" where (C16) 2 = bis(hexadecyl) were deposited and characterised. The conductivities of the LB films of the mixed valence system were found to be ~ 1000 times greater than those of the system lacking TCNQ^ molecules. Multiple layer LB films of trans-4-[4- (dimethylamino)styryl]-1- octadecylpyridinium iodide and trans-4-[4-(dimethylamino)styryl]-1- octadecylquinolinium iodide interleaved with 4,4'-dioctadecyl-3,5,3',5' -tetramethyldipyrrylmethene hydrobromide were deposited. The materials form an interlocking bilayer structure which renders their LB films exceptionally well-organised. The films’ second harmonic generation was investigated and one film was found to give the largest second harmonic signal yet seen from an LB structure. | en_UK |
| dc.identifier.uri | http://dspace.lib.cranfield.ac.uk/handle/1826/10404 | |
| dc.language.iso | en | en_UK |
| dc.publisher | Cranfield University | en_UK |
| dc.rights | © Cranfield University, 1991. All rights reserved. No part of this publication may be reproduced without the written permission of the copyright holder. | en_UK |
| dc.title | Electrical, magnetic and optical characterisation of donor-acceptor systems | en_UK |
| dc.type | Thesis or dissertation | en_UK |
| dc.type.qualificationlevel | Doctoral | en_UK |
| dc.type.qualificationname | PhD | en_UK |