Buscaglia, Vincenzo

Carda, J. B.

Nanni, Paolo

Peir? ?lvarez, M.

Testino, Andrea

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Toledo, Spain, 18-22 June, 2006                                                                                                300 / 373 
 
 
CP-O-11           Õ Back 
 
SYNTHESIS OF ZnO IN AQUEOUS MEDIA. INFLUENCE OF SEVERAL SYNTHESIS PARAMETERS ON PARTICLE SIZE 
AND SHAPE 
M. PEIRÓ ÁLVAREZ1, A. TESTINO2, V. BUSCAGLIA3, P. NANNI2, J.B. CARDA1 
1Universitat Jaume I, Campus de Riu Sec, Castellon, Spain. 
2Università Degli Studi di Genova, Genova, Italy. 
3Consiglio Nazionale di Ricerca, Genova, Italy. 
peiro@sg.uji.es 
 
 
ZnO is a material widely studied in recent years due to its properties and applications. ZnO is a large gap 
band (3.3-3.6 eV) n-type semiconductor and shows both photoconductivity and photocatalytic activity. 
ZnO nanoparticles also show size dependent electronic and optical properties. For these reasons, ZnO 
nanoparticles have been widely used for catalytic, electronic and luminescent devices, pigments and 
components for the pharmaceutical and cosmetic industries. 
In the present work, nanoparticles of ZnO have been synthesized by precipitation from aqueous solutions 
using Zn(NO3)2 as precursor and NaOH as a base. The precipitation experiments have been performed in a 
small batch reactor. Injection of the reactant solutions has been accomplished by means of peristaltic 
pumps. The influence of several experimental parameters, such as concentration of the reactants, 
temperature, pH and stirring rate, on the size and shape of the final particles has been systematically 
investigated. The morphology changes from ellipsoidal particles to star-like particles and to spheres. The 
size can be tailored in the range 100 to 2000 nm. All these information can be summarized in a 
morphology map. Continuous production of fine ZnO particles has been also investigated by means of a 
tubular reactor. 
 
 
 
CP-O-12           Õ Back 
 
SINTERING AND PROPERTIES OF Ba3ZnTa2O9 / Cu BASED MULTILAYER CERAMIC CAPACITORS 
S. MARINEL1, F. ROULLAND2, S. D'ASTORG1 
1CRISMAT Laboratory, Caen, France.  
2Temex Ceramics, Pessac, France. 
sylvain.marinel@ensicaen.fr 
 
 
The dielectric Ba(Zn1/3Ta2/3)O3 (BZT) is a perovskite type material which exhibits attractive dielectric 
properties namely, a low losses factor (tan(δ) <10-3), a relatively high permittivity (εr around 30) and a 
low temperature coefficient of the permittivity  (|TCe|<100 ppm/°C) at high frequencies (from MHz to  
GHz). These properties allow to use this ceramic for fabricating type I multilayer chip capacitors. 
Moreover it has been recently established that BZT ceramic can be sintered at as low temperature as 
1050°C owing to the use of the addition of B2O3+LiF combined with a slight non-stoechiometry. It can be 
mentioned that the usual sintering temperature of BZT is around 1500°C. This sintering temperature 
lowering has permitted  to process copper based multilayer ceramic capacitors. Obviously, the use of 
copper as inner electrodes implies that the sintering process must be performed in a foaming 
atmosphere. The paper presents hence the manufacturing as well as the microstrucure and the 
dielectrics properties of copper based multilayer ceramics capacitors. It is shown that the process allows 
to manufacturing high performance and cheaper type I ceramics capacitors. 
 
 


Synthesis of ZnO in aqueous media. Influence of several synthesis parameters on particle size and shape

http://puma.isti.cnr.it/rmydownload.php?filename=cnr.ieni/cnr.ieni.ge/2006-A6-022/2006-A6-022.pdf

Synthesis of ZnO in aqueous media. Influence of several synthesis parameters on particle size and shape

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