Sahoo, Ganesh Kumar (2009) Synthesis and Characterization of BaTiO3 Prepared by Molten Salt Synthesis Method. MTech thesis.
The study first optimized the different processing parameters e.g. salt systems, heat treatment temperature, holding time. By NaOH-KOH based salt system phase pure powder can be prepared at 175oC. NaCl-KCl based system produced phase pure powder at 700oC. LiCl-KCl based system failed to produce phase pure BaTiO3 powder. Crystallite size of the synthesized powder found to be varying 30-43 nm depending on the processing time and temperature. TEM analysis revealed that particle size in the range of 70-100 nm. It has been observed that NaOH-KOH system synthesized powder can be densified (98%) at a temperature 1225oC. Interestingly ultrafine grain size (200-500 nm) retained in highly dense sintered sample. In case of NaCl-KCl based powder only 91% density achieved, microstructure shows significant amount of porosity. Dielectric constant and loss factor of the sintered samples (εr =1400 and tanδ = 2% at 1 kHz) are on a par with BaTiO3 prepared via conventional sintered sample. NaOH-KOH salt based prepared sample showed almost flatten Curie peak and NaCl-KCl salt system prepared sample showed broad Curie peak with a Curie temperature of 115oC. The peak shift and broadening can be explained qualitatively from temperature dependence of volume fraction between surface cubic layer, bulk tetragonal layer, and gradient-lattice-strain layer (GLSL).
|Item Type:||Thesis (MTech)|
|Uncontrolled Keywords:||BaTiO3,NaOH,KOH,Dielectric ,Particle size|
|Subjects:||Engineering and Technology > Ceramic Engnieering|
|Divisions:||Engineering and Technology > Department of Ceramic Engineering|
|Deposited By:||sahoo ganesh kumar|
|Deposited On:||23 Jun 2009 22:42|
|Last Modified:||23 Jun 2009 22:42|
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