Biomedical Engineering Reference
In-Depth Information
were weighted using High Precession (0.001mg) Electronic Balance ES 225
SM-DR obtained from Switzerland. h ese raw chemicals were mixed thor-
oughly in the liquid medium (acetone) according to the following stoichio-
metric formula:
Bi
2
O
3
+ Fe
2
O
3
2BiFeO
3
(13.3)
h is mixture of raw materials was thoroughly ground for more than
5 hours in agate mortar and pestle and then calcined at 600-700 C for
two hours. h e process of i ring and mixing was repeated a number of
times. Finally, the cylindrical pellets were prepared by applying pressure of
5 tones/cm
2
(498 MPa) using a hydraulic press. By optimizing the time and
temperature condition for sintering, these pellets were sintered at ~880 C
for 5-10 minutes. h e pure sample shows metallic color which gradually
changes into reddish color. Silver electrodes were used on the top and bot-
tom surface of the pellets for electrical measurements. A l owchart of the
synthesis of pure bismuth ferrite ceramic is shown in Figure 13.7.
Bi
2
O
3
Fe
2
O
3
Mixing & milling for 5 hours
Calcination at 600°C for 8 hours
Re-grinding for 5 hours
Re-calcination at 600°C for 8 hours
Grinding for 1 hours
Pelletization by applying Pressure
of 5 tones/cm
2
Sintering at 880°C for 5-10 minutes
Electroding
Testing
Figure 13.7
Flowchart of the synthesis of pure bismuth ferrite.
