Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
CONTROLLING THE STRUCTURE OF TRANSPARENT LANGMUIR-BLODGETT-FILMS FOR NONLINEAR-OPTICAL APPLICATIONS
Autore:
ASHWELL GJ; JACKSON PD; JEFFERIES G; GENTLE IR; KENNARD CHL;
Indirizzi:
CRANFIELD UNIV,CTR MOLEC ELECTR CRANFIELD MK43 0AL BEDS ENGLAND UNIV QUEENSLAND,DEPT CHEM BRISBANE QLD 4072 AUSTRALIA
Titolo Testata:
Journal of materials chemistry
fascicolo: 2, volume: 6, anno: 1996,
pagine: 137 - 141
SICI:
0959-9428(1996)6:2<137:CTSOTL>2.0.ZU;2-X
Fonte:
ISI
Lingua:
ENG
Soggetto:
2ND HARMONIC-GENERATION; 2ND-HARMONIC GENERATION; MONOLAYERS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
24
Recensione:
Indirizzi per estratti:
Citazione:
G.J. Ashwell et al., "CONTROLLING THE STRUCTURE OF TRANSPARENT LANGMUIR-BLODGETT-FILMS FOR NONLINEAR-OPTICAL APPLICATIONS", Journal of materials chemistry, 6(2), 1996, pp. 137-141

Abstract

Langmuir-Blodgett (LB) multilayers of -alkyl-4-[2-(4-docosyloxyphenyl)ethenyl]pyridinium bromide, CBH2n+1-Py(+)-CH=CH-C6H4-O-C22H45Br- (dyeI), are centrosymmetric (Y-type) for n less than or equal to 6 and non-centrosymmetric (Z-type) for 8 less than or equal to n less than or equal to 20. The areas obtained from grazing incidence synchrotron X-ray diffraction indicate that the molecules adopt a 'stretched' rather than a 'U-shaped' configuration and, unlike conventional amphiphilic materials, the long chain homologues do not invert during deposition. The second-harmonic intensity from films of the higher homologues (n greater than or equal to 10) increases quadratically with the number of LB layers (I-2 omega(N) = I-2 omega(1)N-2) whereas for the lower homologues (n less than or equal to 6) the intensity is negligible for evennumbers of layers. The nonlinear optical properties of the sulfur (dye II), selenium (dye III) and quinolinium (dye TV) analogues are also reported and, in each case, quadratic enhancement of the second-harmonic intensity has been observed for suitable combinations of alkyl chain lengths. The second-order susceptibility, chi((2))(zzz), of a 100 layer LB film of (E)-N-dodecyl-4-[2-(4-docosyloxyphenyl)ethenyl] quinolinium bromide (dye IV) is 20 pm V-1.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 21/09/20 alle ore 02:41:20