The nucleation and growth phenomena in the generation of monodisperse Ti02 powders by the hydrolysis of Ti(OC2H5)4 in ethanol solution have been investigated. Induction time was measured by noting the time of an abrupt change in the turbidity of the reacting solution. Shorter induction times were observed with higher reactant concentrations. The growth rate was measured in situ by photon correlation spectroscopy and compared with transmission electron microscopy. The rate-limiting step during growth is the liquid-phase diffusion of polymeric species to the surface of the particles.

Camber (curvature) development during cofiring a two-layered structure of Ag film/low-dielectric-constant, low-temperature cofired ceramic (LTCC) green tape has been investigated. At a given thickness of Ag film, both the camber and camber rate decrease linearly with increasing the square thickness of LTCC. Densification mismatch between Ag and LTCC is attributed to be the root cause for the camber generation during cofiring. Mathematical analysis is made to theoretically describe the camber development, and the results show a fairly good agreement with experimental observations.

Stress development during the constrained sintering of a sandwich structure of alumina/glass/alumina has been studied. Stress distribution in the glass layer was calculated using a finite element method. The shear stress exhibited a maximum at the edge of the alumina/glass interface. The in-plane tensile stress, formed during constrained sintering, decreased from the interface of the alumina/glass to the middle of the glass in the z-direction, but increased from the edge to the center of glass in the x-y direction. This in-plane tensile stress reduces the driving force of densification, resulting in a larger x-y shrinkage and higher densification in the middle of the glass.

and calcium borate (CaB 2 O 4 ), with crystalline wollastonite (CaSiO 3 ) the major phase. The crystallization kinetics of wollastonite followed an Avrami equation. The results of the present study showed an apparent activation energy of 200-260 kJ/mol. Combined with the results of reduced growth rate (growth rate × viscosity) and thermal analysis, the rate-controlling mechanism of crystallization appeared to be a two-dimensional surface nucleation growth. As the amount of crystalline wollastonite increased, the dielectric constant decreased, but the thermal expansion coefficient remained relatively unchanged.

The development of camber during the cofiring of a twolayered structure of Ni-electrode/BaTiO 3 -dielectric as a function of temperature has been investigated. At a given thickness of Ni electrode, less camber and camber rate with increasing thickness of BaTiO 3 dielectric have been observed. This phenomenon is attributed to the densification mismatch between the Ni electrode and the BaTiO 3 dielectric during cofiring. The mathematical analysis of camber development, based on a viscous model, shows significant agreement with experimental observations.