Mechanical alloying has been used successfully to produce
nanocrystalline powders of CaCu3Ti4O12 (CCTO), for the first time, using
two different experimental procedures. The milled CCTO were studied by
X-ray powder diffraction, infrared and Raman scattering spectroscopy.
For two different milling procedures, CCTO was obtained after a couple
of hours of milling (in average 30 h of milling, depending on the
reaction procedure). The X-ray diffraction (XRD) patterns indicate that
the crystallite size is within the range of 20-35 nm. After 100 h of
milling the formation of CCTO was confirmed by X-ray powder diffraction
in both procedures, with good stability. We also prepare the CCTO
ceramic using the traditional procedure described in the literature and
compared the physical properties of these samples with those ones
obtained by milling process and good agreement was observed. The
infrared and Raman scattering spectroscopy results suggest that the
increase of the milling time leads to the formation of nanocrystalline
CCTO, as seen by XRD analysis. These materials are attractive for
capacitor applications and certainly for microelectronics, microwave
devices (cell mobile phones for example), where the decrease of the size
of the devices are crucial. This milling process presents the advantage
that melting is not necessary and the powder obtained is nanocrystalline
with extraordinary. mechanical properties. The material can be compacted
and transformed in solid ceramic samples or used in others procedures of
film preparation. The high efficiency of the process opens a way to
produce commercial amount of nanocrystalline powders. Due to the
nanocrystalline character of this powder, their mechanical properties
have changed and for this reason a pressure of 1 GPa is enough to shape
the sample into any geometry. (C) 2002 Elsevier Science B.V. All rights
reserved.
%0 Journal Article
%1 WOS:000179622800009
%A Almeida, AFL
%A de Oliveira, RS
%A Goes, JC
%A Sasaki, JM
%A Souza, AG
%A Mendes, J
%A Sombra, ASB
%C PO BOX 564, 1001 LAUSANNE, SWITZERLAND
%D 2002
%I ELSEVIER SCIENCE SA
%J MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED
TECHNOLOGY
%K XRD} oxide; titanium {ceramics;
%N 3
%P 275-283
%R 10.1016/S0921-5107(02)00379-3
%T Structural properties of CaCu3Ti4O12 obtained by mechanical alloying
%V 96
%X Mechanical alloying has been used successfully to produce
nanocrystalline powders of CaCu3Ti4O12 (CCTO), for the first time, using
two different experimental procedures. The milled CCTO were studied by
X-ray powder diffraction, infrared and Raman scattering spectroscopy.
For two different milling procedures, CCTO was obtained after a couple
of hours of milling (in average 30 h of milling, depending on the
reaction procedure). The X-ray diffraction (XRD) patterns indicate that
the crystallite size is within the range of 20-35 nm. After 100 h of
milling the formation of CCTO was confirmed by X-ray powder diffraction
in both procedures, with good stability. We also prepare the CCTO
ceramic using the traditional procedure described in the literature and
compared the physical properties of these samples with those ones
obtained by milling process and good agreement was observed. The
infrared and Raman scattering spectroscopy results suggest that the
increase of the milling time leads to the formation of nanocrystalline
CCTO, as seen by XRD analysis. These materials are attractive for
capacitor applications and certainly for microelectronics, microwave
devices (cell mobile phones for example), where the decrease of the size
of the devices are crucial. This milling process presents the advantage
that melting is not necessary and the powder obtained is nanocrystalline
with extraordinary. mechanical properties. The material can be compacted
and transformed in solid ceramic samples or used in others procedures of
film preparation. The high efficiency of the process opens a way to
produce commercial amount of nanocrystalline powders. Due to the
nanocrystalline character of this powder, their mechanical properties
have changed and for this reason a pressure of 1 GPa is enough to shape
the sample into any geometry. (C) 2002 Elsevier Science B.V. All rights
reserved.
@article{WOS:000179622800009,
abstract = {Mechanical alloying has been used successfully to produce
nanocrystalline powders of CaCu3Ti4O12 (CCTO), for the first time, using
two different experimental procedures. The milled CCTO were studied by
X-ray powder diffraction, infrared and Raman scattering spectroscopy.
For two different milling procedures, CCTO was obtained after a couple
of hours of milling (in average 30 h of milling, depending on the
reaction procedure). The X-ray diffraction (XRD) patterns indicate that
the crystallite size is within the range of 20-35 nm. After 100 h of
milling the formation of CCTO was confirmed by X-ray powder diffraction
in both procedures, with good stability. We also prepare the CCTO
ceramic using the traditional procedure described in the literature and
compared the physical properties of these samples with those ones
obtained by milling process and good agreement was observed. The
infrared and Raman scattering spectroscopy results suggest that the
increase of the milling time leads to the formation of nanocrystalline
CCTO, as seen by XRD analysis. These materials are attractive for
capacitor applications and certainly for microelectronics, microwave
devices (cell mobile phones for example), where the decrease of the size
of the devices are crucial. This milling process presents the advantage
that melting is not necessary and the powder obtained is nanocrystalline
with extraordinary. mechanical properties. The material can be compacted
and transformed in solid ceramic samples or used in others procedures of
film preparation. The high efficiency of the process opens a way to
produce commercial amount of nanocrystalline powders. Due to the
nanocrystalline character of this powder, their mechanical properties
have changed and for this reason a pressure of 1 GPa is enough to shape
the sample into any geometry. (C) 2002 Elsevier Science B.V. All rights
reserved.},
added-at = {2022-05-23T20:00:14.000+0200},
address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND},
author = {Almeida, AFL and de Oliveira, RS and Goes, JC and Sasaki, JM and Souza, AG and Mendes, J and Sombra, ASB},
biburl = {https://www.bibsonomy.org/bibtex/27a80cff2d1b364b326f693326038ed95/ppgfis_ufc_br},
doi = {10.1016/S0921-5107(02)00379-3},
interhash = {8b9669e297b948ba7f638a975e879967},
intrahash = {7a80cff2d1b364b326f693326038ed95},
issn = {0921-5107},
journal = {MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED
TECHNOLOGY},
keywords = {XRD} oxide; titanium {ceramics;},
number = 3,
pages = {275-283},
publisher = {ELSEVIER SCIENCE SA},
pubstate = {published},
timestamp = {2022-05-23T20:00:14.000+0200},
title = {Structural properties of CaCu3Ti4O12 obtained by mechanical alloying},
tppubtype = {article},
volume = 96,
year = 2002
}