1. Solid State Reaction: General
- Reaction between the solids
Advantages
1. Simple apparatus (ball milling,
A+B
rotatory evaporator)
2. Inexpensive (cost-effective)
Disadvantages
1. Wide particle-size distribution
2. Coarse particle size ( ≥1µm)
3. Contamination during mixing
4. High temperature is required for reaction
especially when the particle size is large
C+A+B
or when the mixing is insufficient
5. Compositional fluctuation due to
the incomplete reaction
6. Difficult to control the particle shape
Advanced Electronic Ceramics I (2004)
Rotatory evaporator
http://www.buchi-analytical.com/file/2/ct_1120_ctDownload1.pdf
Advanced Electronic Ceramics I (2004)

2. Solid State Reaction
AO
BO2
Starting powder Incomplete reaction Proper reaction Strong bond
due to excessive
reaction
ABO3
A+
AO BO2 AO BO2
L ∝ t1/2
B2+
L
Ceramic Processing: Powder Preparation and Forming, Ceramic Society of Japan (1984)
Advanced Electronic Ceramics I (2004)
Solid State Reaction: Particle size
(1) coarse particles
AO
AO
ABO3
BO2 BO2
L ∝ t1/2
(2) fine particles
AO
ABO3
BO2
For complete reaction, t1 = 4t2
Ceramic Processing: Powder Preparation and Forming, Ceramic Society of Japan (1984)
Advanced Electronic Ceramics I (2004)

3. Solid State Reaction: Particle-size distribution
At the presence of a coarse particle in a fine matrix particles
AO
ABO3
BO2 BO2
Strong bond between particles can be occurred
when the reaction time increased in order to achieve
complete reaction
Ceramic Processing: Powder Preparation and Forming, Ceramic Society of Japan (1984)
Advanced Electronic Ceramics I (2004)
Solid State Reaction: mixing
(1) good mixing AO BO2
AO
ABO3
BO2
(2) bad mixing
AO
ABO3
BO2
Ceramic Processing: Powder Preparation and Forming, Ceramic Society of Japan (1984)
Advanced Electronic Ceramics I (2004)

4. Solid State Reaction: other parameters
1. Compaction or filling state
- The reaction occurs and the contact points between two phase
2. Temperature
- the temperature dependence of diffusion coefficient
D = Do exp (-E/RT)
Ceramic Processing: Powder Preparation and Forming, Ceramic Society of Japan (1984)
Advanced Electronic Ceramics I (2004)
Solid State Reaction: BaTiO3
Fig. In-situ X-ray diffraction
BL: γ-BaCO3, BH: β-BaCO3,
T: TiO2, B2T: Ba2TiO4,
BT: BaTiO3, BT3: BaTi3O7,
BaCO3:
BT4: BaTi4O9,
TiO2
B2T formation from ~800oC
BT formation from ~900oC
The completion of BT formation
: ~1200oC
Temperature (oC)
Ceramic Processing: Powder Preparation and Forming, Ceramic Society of Japan (1984)
Advanced Electronic Ceramics I (2004)

5. Solid State Reaction: BaTiO3
Fig. In-situ X-ray diffraction
BL: γ-BaCO3, BH: β-BaCO3,
T: TiO2, B2T: Ba2TiO4,
BT: BaTiO3, BT3: BaTi3O7,
BT4: BaTi4O9,
BaCO3:
TiO2
Avg. size of BaTiO3: 1 µm
(A) avg. size of TiO2: 6.5 µm
(B) avg. size of TiO2: 2.0 µm
(C) avg. size of TiO2: 0.05 µm
In the case of fine powder,
- small B2T formation
- BT formation
Temperature (oC)
at low temperature
Ceramic Processing: Powder Preparation and Forming, Ceramic Society of Japan (1984)
Advanced Electronic Ceramics I (2004)
Solid State Reaction: BaTiO3
Fig. In-situ X-ray diffraction
BL: γ-BaCO3, BH: β-BaCO3,
T: TiO2, B2T: Ba2TiO4,
BT: BaTiO3, BT3: BaTi3O7,
BT4: BaTi4O9,
BaCO3:
TiO2
The curves for the co-precipitated
BaTiO3 powder
- almost no intermediate reaction
- low temperature formation
Temperature (oC)
Ceramic Processing: Powder Preparation and Forming, Ceramic Society of Japan (1984)
Advanced Electronic Ceramics I (2004)

6. Solid State Reaction: BaTiO3
1. Reaction at the contact points
In order to avoid the incomplete reaction,
- smaller particle size
- good mixing
- narrow particle-size distribution
- good compaction between particles
2. Reaction at relatively high temperature
- frequently results the milling the powder aggregates
for further process
- involves the contamination during ball milling
Ceramic Processing: Powder Preparation and Forming, Ceramic Society of Japan (1984)
Advanced Electronic Ceramics I (2004)