ISSN:
1551-2916
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
The authors previously demonstrated that Ba(CH3COO)2-Ti(OC3H7i)4-CH3COOH-H2O-i-C3H7OH solutions containing poly(vinylpyrrolidone) (PVP) can offer crack-free BaTiO3 coatings 〉1 μm thick via noncycled, single-step dip coating. The solutions, however, gelled within a few hours, which cannot be of practicable use in industry. To make the solutions applicable for industrial use, the solution composition has been optimized so that the solutions have sufficient stability in viscosity. Using Ti(OC2H5)4 and C2H5OH instead of Ti(OC3H7i)4 and i-C3H7OH, respectively, high CH3COOH contents and low H2O contents in solutions were effective in suppressing the variation of viscosity with time. A solution of molar composition, Ba(CH3COO)2:Ti(OC2H5)4:PVP:CH3COOH:H2O:C2H5OH = 1:1:0.5:27:4:5, exhibited great stability in viscosity over 900 h at room temperature. Crack-free BaTiO3 films as thick as 0.9 μm could be obtained via noncycled gel film deposition and firing at 700°C. However, the dielectric constant of the 0.9-μm-thick film was as low as 130 at 1 kHz. The films obtained via stepwise firing at 360° and 700°C, on the other hand, were ∼0.6 μm thick, showed good transparency, and had dielectric constants of ∼290 at 1 kHz.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1151-2916.2003.tb03273.x
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