Chemical Vapor Synthesis of Nanocrystalline Oxides

ABSTRACTControlling the oxidation state of iron and the crystal structure of iron containing compounds is the key to improved materials such as iron oxide nanoparticles for cancer treatment or heterogeneous catalysis. Iron oxides contain iron in different oxidation states and form different phases for one valence state (α-Fe3+2O2-3, β- Fe3+2O-32, etc.). Chemical vapor synthesis (CVS) allows the reproducible production of pure nanocrystals with narrow size distribution where particle formation and growth take place in the gas phase. Through the controlled variation of synthesis parameters CVS enables the synthesis of diverse iron oxide phases. In this study the energy for the CVS process is supplied by a hot wall furnace and a microwave plasma. The advantage of an plasma reactor as the first CVS stage is the fast and complete precursor decomposition at low temperatures. This results in a larger process window for the hot wall reactor in the second stage. The nanoparticles are examined regarding their structure, surface and valence by XRD and TEM.

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Boundary layer chemical vapor synthesis of self-organized radial filled-carbon-nanotube structures

Carbon ◽

10.1016/j.carbon.2013.08.001 ◽

2013 ◽

Vol 64 ◽

pp. 516-526 ◽

Cited By ~ 22

Author(s):

F. S. Boi ◽

G. Mountjoy ◽

M. Baxendale

Keyword(s):

Boundary Layer ◽

Carbon Nanotube ◽

Chemical Vapor ◽

Chemical Vapor Synthesis ◽

Self Organized

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Chemical vapor synthesis and luminescence properties of nanocrystalline cubic Y2O3:Eu

Journal of Applied Physics ◽

10.1063/1.371177 ◽

1999 ◽

Vol 86 (6) ◽

pp. 3129-3133 ◽

Cited By ~ 139

Author(s):

A. Konrad ◽

T. Fries ◽

A. Gahn ◽

F. Kummer ◽

U. Herr ◽

...

Keyword(s):

Chemical Vapor ◽

Luminescence Properties ◽

Chemical Vapor Synthesis

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Chemical vapor synthesis and characterization of chromium doped zinc oxide nanoparticles

Journal of the European Ceramic Society ◽

10.1016/j.jeurceramsoc.2007.02.152 ◽

2007 ◽

Vol 27 (13-15) ◽

pp. 4333-4337 ◽

Cited By ~ 43

Author(s):

Wei Jin ◽

In-Kyum Lee ◽

Alexander Kompch ◽

Udo Dörfler ◽

Markus Winterer

Keyword(s):

Zinc Oxide ◽

Zinc Oxide Nanoparticles ◽

Chemical Vapor ◽

Synthesis And Characterization ◽

Oxide Nanoparticles ◽

Chemical Vapor Synthesis

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Influence of the Time-Temperatur-Profile on Powder Characteristics of Nanocrystalline Anatase (TiO2) produced by Chemical Vapor Synthesis

MRS Proceedings ◽

10.1557/proc-1056-hh08-07 ◽

2007 ◽

Vol 1056 ◽

Cited By ~ 1

Author(s):

Ruzica Djenadic ◽

Sankhanilay Roy Chowdhury ◽

Marina Spasova ◽

Andreas Gondorf ◽

Erdal Akyildiz ◽

...

Keyword(s):

Gas Flow ◽

Flow Reactor ◽

Chemical Vapor ◽

Titanium Isopropoxide ◽

Degree Of Crystallinity ◽

Chemical Vapor Synthesis ◽

Nanocrystalline Particles ◽

Powder Characteristics ◽

Gas Flow Reactor ◽

Nanocrystalline Anatase Tio2

ABSTRACTChemical Vapor Synthesis (CVS) is the conversion of molecular species into nanocrystalline particles by chemical reactions in a gas flow reactor. Pure anatase nanoparticles are generated in a hot wall reactor from titanium isopropoxide using different time-temperature-profiles. The time-temperature-profile (T(t)-profile) in the gas phase of the reactor has a profound influence on the particle characteristics such as particle microstructure and surface chemistry and, therefore, on the quality of the powder consisting of nanocrystalline particles. In this study a simple reaction-coagulation-sintering model (CVSSIN) was used to predict influence of the T(t)-profile on the powder characteristics. The as-synthesized anatase powders show a very high degree of crystallinity, primary particle of about 10 nm sizes and a low degree of agglomeration.

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