Synthesis and characterization of high dielectric constant material based on Er-doped BaTiO3 for capacitor applications
High dielectric constant material becomes an important parameter to be used as capacitor for storage in most electronic devices due to miniaturization trend of smart devices and electronic gadgets. BaTiO3 was used in this study as it was reported to have a high dielectric constant (εr= 4000-10000...
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| Format: | Thesis |
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| Language: | English |
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| Online Access: | http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/77424/1/Page%201-24.pdf http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/77424/2/Full%20text.pdf http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/77424/3/Declaration%20Form.pdf |
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| Summary: | High dielectric constant material becomes an important parameter to be used as
capacitor for storage in most electronic devices due to miniaturization trend of smart
devices and electronic gadgets. BaTiO3 was used in this study as it was reported to have
a high dielectric constant (εr= 4000-10000) at Curie temperature (TC) around 110˚C.
Furthermore, it was reported that by doping Erbium (Er) into BaTiO3, it can improve
the dielectric properties of BaTiO3. BaTiO3 and Er-doped BaTiO3 with composition of
Ba1-xErxTiO3 in the range of (0 ≤ x ≤ 0.01) have been synthesized via conventional solid
state reaction method. The characterizations of these compositions were made using
X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) analysis and
Impedance Analyzer analysis. XRD analysis shows that BaTiO3 and Er-doped BaTiO3
has phase pure after heating at 1400˚C. Both BaTiO3 and Er-doped BaTiO3 exhibit
tetragonal structure with space group of P4mm. Solid solution limit of Er-doped
BaTiO3 composition is beyond x=0.01. For structural analysis, Rietveld refinement
analysis were done on BaTiO3 for 5 models (A, B, C, D and E) to find the suitable
atomic position with low 2 value to be used as standard model to refine other Er-doped
BaTiO3 samples. Model C is the best model with low 2 value of 3.808. With Rietveld
refinement analysis, study on incorporation of Er into the A-site and B-site of
perovskite ABO3 structure was done. The result indicates that Er can be at both side
either A or B site because of the 2 value that is very similar. For microstructural
analysis, SEM was used to study the grain size effect by doping Er into BaTiO3. The
smallest grain size for Ba1-xErxTiO3 was 3.76 m at x=0.0075. For electrical properties,
the composition of Ba1-xErxTiO3 at x=0.0075 has the highest dielectric constant value,
εr= ~ 6500 as compared to pure BaTiO3 with dielectric constant value, εr= ~ 5200.
Instead of that, the sample at x=0.0075 has low dielectric loss with value less than 0.1.
The highest capacitance value for x=0.0075 at the highest dielectric constant value is
C= ~4 x 10-9 Fcm-1 with total conductivity, ζ= 4 x 10-7Scm-1. The Capacitance-Voltage
(C-V) characteristic were measured from 0 to 30 V and all the samples show a high
capacitance by increasing the voltage up to 30 V with no signal of breakdown region.
The sample with the highest dielectric constant, low loss and good C-V characteristic is
the sample with x= 0.0075. |
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