xi
LIST OF FIGURES
1.1 Flowchart of scope of study.
2.1 Perovskite structure
2.2 Structure of CaCu
3
Mn
4
O
12
indicating a the MnO
6
polyhedral structure; b the cubooctahedral AO
12
polyhedra; and c the 12-coordinated polyhedra around the A’ Cu
2+
Mn
3+
cation. 2.3 Ferromagnetic
ordering. 2.4
Antiferromagnetic ordering. 2.5 Ferrimagnetic
ordering. 2.6
Simple illustration of a paramagnetic probe made up from miniature magnets.
2.7 Giant magnetoresistive
effect.
2.8 Flow process of CaCu
3
Mn
4
O
12
synthesis by wet-chemistry method. 2.9
Flow process of CaCu
3
Mn
4
O
12
synthesis by solid state reaction method.
2.10 Distribution of liquid among particles during slow drying: A before
drying, B at the early stage of drying, C at the end of drying, D fully dried.
2.11 Powder pressing method.
2.12 Illustration of change in shape and change of bimodal pore
distribution during
compaction. 2.13
The sintering process for ceramics. The shrinkage of the workpiece during sintering is due to the elimination of the pores between
particles; a Green compact, b Connecting necks have been formed, c Size of pores between particles is greatly reduced
particles, d Only small pores remain - fully sintered.
3.1 Flow process of sol-gel method.
6
10 12
14 15
15 16
18 21
22
25
26 27
30
32
xii 3.2
Evaporating process of sample precursor by using heater. 3.3
Calcination profile of sample precursor sol-gel method. 3.4
Grinding of powder to get into fine powder before compaction. 3.5
Uniaxial hydraulic press machine. 3.6
Filling the powder into pressing machine mold in powder pressing process.
3.7 Sintering profile of the sample pellet sol-gel method.
3.8 Flow chart of solid state reaction method.
3.9 Calcination profile of precursor powder for 1½ hours solid
state reaction.
3.10 Calcination profile of precursor powder for 5 hours solid state reaction.
3.11 Sintering profile of sample pellet for ½ hours solid state reaction.
3.12 Furnace used for sintering process.
3.13 The flow chart of sample testing process.
3.14 Brukers X-ray Diffraction D8.
3.15 Sample is placed on a plate to support it during clamping at scanning platform.
3.16 Scanning electron microscope SEM.
3.17 Impedance Analyzer.
3.18 Clamping of the sample during electrical testing.
4.1 The CaCu
3
Mn
4
O
12
samples. 4.2
XRD pattern for CaCO
3
powder ICDD 047-1743. 4.3
XRD pattern for CuO powder ICDD 44-0706.
4.4 XRD patterns for CaCu
3
Mn
4
O
12
samples synthesized through sol- gel method.
4.5 XRD pattern of CaOH
2
powder. 4.6
XRD pattern of CuO powder. 4.7
XRD pattern of MnO
2
powder. 34
35 35
36 36
37 38
40
40
41
41 42
43 44
45 46
46
47 49
49 50
54 54
55
xiii 4.8
XRD pattern of KClO
3
powder. 4.9
XRD patterns for CaCu
3
Mn
4
O
12
synthesized through solid state reaction at calcination temperature of 800°C for 1½ hours.
4.10 XRD patterns for CaCu
3
Mn
4
O
12
synthesized through solid state reaction at calcination temperature of 800°C for 5 hours.
4.11 SEM image of CaCu
3
Mn
4
O
12
powder synthesized by sol-gel method.
4.12 EDS observation on CaCu
3
Mn
4
O
12
powder synthesized by sol-gel method.
4.13 SEM image of CaCu
3
Mn
4
O
12
pellet synthesized by sol-gel method. 4.14 EDS observation on CaCu
3
Mn
4
O
12
pellet synthesized by sol-gel method.
4.15 SEM image of CaCu
3
Mn
4
O
12
powder synthesized by solid state reaction A.
4.16 EDS observation on CaCu
3
Mn
4
O
12
powder synthesized by solid state reaction A.
4.17 SEM image of CaCu
3
Mn
4
O
12
pellet synthesized by solid state reaction A.
4.18 EDS observation on CaCu
3
Mn
4
O
12
pellet synthesized by solid state reaction
A. 4.19 SEM image of CaCu
3
Mn
4
O
12
powder synthesized by solid state reaction B.
4.20 EDS observation on CaCu
3
Mn
4
O
12
powder synthesized by solid state reaction B.
4.21 SEM image of CaCu
3
Mn
4
O
12
pellet synthesized by solid state reaction B.
4.22 EDS observation on CaCu
3
Mn
4
O
12
pellet synthesized by solid state reaction
B. 4.23
Graph of conductivity value of CaCu
3
Mn
4
O
12
samples
.
4.24 Graph of conductivity versus density of CaCu
3
Mn
4
O
12
samples. 55
56
56
59
60
61 62
63
64
65
66
68
69
70
71
72 73
xiv
LIST OF ABBREVIATIONS
CaCu
3
Mn
4
O
12
- Calcium Cuprum Mangan Oxide
TMOs - Transition
Metal Oxides
CCMO -
Calcium Cuprum Mangan Oxide
CuO - Copper
II Oxide
CaCO
3
- Calcium Carbonate
CaOH
2
- Calcium Hydroxide
MnO
2
- Manganese Oxide
KClO
3
- Potassium Chlorate
MnNO
3 2
.4H
2
O - Manganese Nitrate
Tetrahydrate MR
- Magnetoresistance
GMR - Giant
Magnetoresistance CMR
- Colossal Magnetoresistance
FCC - Face
Center Cubic
XRD - X-Ray
Diffraction SEM
- Scanning Electron
Microscopy EDS
- Energy Dispersive X-Ray Spectroscopy
RT - Room
Temperature σ - Conductivity
ICDD - International
Center for
Diffraction Data
1
CHAPTER 1
INTRODUCTION
1.1 Introduction to Calcium Cuprum Mangan Oxide CaCu
