Preparation of Core-Shell BaTiO~3 Particles Coated with MgO

MgO is a well-known additive to BaTiO3 powder for MLCC application. A nano-coating process was investigated to produce an MgO shell layer onto BaTiO 3 core powder. Several deposition reaction routes were examined to find out that a magnesium nitrate-urea system worked very well, if not the best. The solution-state reaction gave Mg 5(CO3)4(OH)2·4H 2O as confirmed by XRD, which later turned to MgO upon calcination at 600°C. The core-shell morphology was characterized using SEM and TEM whereas the composition of the shell layer was determined via ICP-AES and XRF. The composition of the MgO shell layer was rather easily controlled by adjusting initial amounts of reactants.