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Titolo:
GAS-PHASE SYNTHESIS OF NANOPARTICLES OF GROUP-12 CHALCOGENIDES
Autore:
PICKETT NL; RIDDELL FG; FOSTER DF; COLEHAMILTON DJ; FRYER JR;
Indirizzi:
UNIV ST ANDREWS,SCH CHEM ST ANDREWS KY16 9ST FIFE SCOTLAND UNIV ST ANDREWS,SCH CHEM ST ANDREWS KY16 9ST FIFE SCOTLAND UNIV GLASGOW,DEPT CHEM GLASGOW G12 8QQ LANARK SCOTLAND
Titolo Testata:
Journal of materials chemistry
fascicolo: 9, volume: 7, anno: 1997,
pagine: 1855 - 1865
SICI:
0959-9428(1997)7:9<1855:GSONOG>2.0.ZU;2-#
Fonte:
ISI
Lingua:
ENG
Soggetto:
CHEMICAL VAPOR-DEPOSITION; MOCVD LAYER GROWTH; STRUCTURAL CHARACTERIZATION; THERMAL-DECOMPOSITION; ZNSE; ADDUCT; DIETHYLZINC; PYROLYSIS; PARTICLES; DIETHYLTELLURIUM;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
38
Recensione:
Indirizzi per estratti:
Citazione:
N.L. Pickett et al., "GAS-PHASE SYNTHESIS OF NANOPARTICLES OF GROUP-12 CHALCOGENIDES", Journal of materials chemistry, 7(9), 1997, pp. 1855-1865

Abstract

The effect of pyridine addition upon the gas-phase reactions of hydrogen sulfide (H2S) or hydrogen selenide (H2Se) with either dimethylcadmium (Me2Cd) or dimethylzinc (Me2Zn) has been investigated. The deposits of CdS, CdSe, ZnSe or ZnS which form have been analysed by powder X-ray diffraction (PXRD), elemental analysis and transmission electron microscopy (TEM). At ambient temperatures the deposits consist of particles in the nanocrystalline size range of the hexagonal phase. The average particle size within the deposits is dependent upon the concentration of pyridine in the gas phase, the temperature at which the reactants are mixed and, in the case of ZnSe, whether an inert (He) or reducing (H-2) carrier gas is used. At ambient temperatures in an inert carrier gas, the control of particle size exerted by pyridine decreases in the order ZnS > CdS > CdSe > ZnSe, although in hydrogen, the prereaction between Me2Zn and H2Se could be almost completely eliminated by raising the temperature. Further investigation of CdS deposits have been carried out by photoacoustic spectroscopy (PAS) to access the band-gap, and solid-state C-13 and Cd-113 NMR to probe the surface state of the particles. Elemental analysis and the NMR studies suggest that pyridine binds through the lone pair of the nitrogen to surface metal atoms on growing particles, inhibiting further particle growth. The particle size is greatly dependent upon the strength of the pyridine-surface metal atom interaction, the acidity of the EH bond (E = S or Se) andthe polarity of the MMe bond (M = Zn or Ca). In hydrogen, it is proposed that amide species may form and be responsible for growth inhibition.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 01/10/20 alle ore 15:47:11