Hydrothermal Synthesis of Barium Titanate with Titanium Oxide as Precursor

• Main Authors: Pei-Yi Chiang, 江珮儀
• Other Authors: Hui-Jean Chiang
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/74983125935150979374

碩士 === 國立新竹教育大學 === 自然教育學系碩士班 === 99 === In this research, TiO2 was chosen as precursor, Ba(OH)2‧8H2O or Ba(NO3)2 as Ba2+ source and NaOH as alkali source to proceed hydrothermal synthesis of barium titanate at 220℃for 48 hours. The effect of NaOH concentration from 1 to 10M, the degree of fill of autoclave container from 50% to 80% and different Ba2+ ion source were all investigated for the influence on crystal phase and particle size of BaTiO3 product. The investigate results that an amorphous product with impurities was obtained as NaOH concentration below 3M, and that the purity of product decreased with the formation of by-products as NaOH concentration above 7M. Barium titanate particles synthesized from Ba(OH)2‧8H2O was found to have a probability of containing lattice defect of OH– which would influence their physical properties. The products with larger size and lower tetragonality was obtained as the degree of fill above 60%. By adjusting NaOH concentration between 4~6M and the degree of fill close to 60%, Barium titanate particles with smaller average size and better tetragonality could be obtained. The preferred tetragonal barium titanate particles with average size about 150nm could be synthesized from Ba(NO3)2 and TiO2 as precursor with NaOH concentration between 4~5M and the degree of fill of 60%.