G Processing and characterization of CaTiO 3 perovskite ceramics
Calcium titanate (CaTiO3) ceramics with perovskite structure were produced by solid state reaction. Calcium carbonate (CaCO3) and titanium dioxide (TiO2) were mixed (in molar ratios 1/1 and 3/2), and the obtained mixtures were calcined at 1150 °C in successive thermal cycles. The obtained samples were characterized by differential thermal analysis, thermogravimetry, X-ray diffraction, measurement of particle size distribution and linear thermal shrinkage. XRD results indicated that the samples have perovskite CaTiO3 structure with small amount of secondary CaO and TiO2 phases, and their phase composition depends on the heat treatment conditions. The measured values of electrical resistivity were within the characteristic range of insulating materials and approach values corresponding to semiconducting ceramics.
Microsystem packaging: lessons from conventional low cost IC packaging
This paper describes some of the issues associated with the packaging of microsystems and how packaging can influence their reliability and performance. The importance of early consideration in the design cycle of packaging, and the environment in which the microsystem will be placed, is stressed. It illustrates how the IC packaging industry has striven to overcome the problems of residual stress, stress minimization, hermeticity, and improved thermal performance in their packages and how this can be applied to microsystem packaging. Packaging problems specific to microsystems are identified.
Synthesis and photoluminescence properties of Eu3+-doped AZrO3 (A = Ca, Sr, Ba) perovskite
Nanocrystalline europium-doped AZrO(3) (A=Ca, Sr, Ba) were prepared by Pechini-type complex sol-gel method. The attained results of XRD and SEM suggest that this synthesis method appears to be an efficient method to prepare the luminescence materials AZrO(3):Eu with high homogeneity and purity. At the same time, the photoluminescence results indicate that Eu3+ ions in monoclinic CaZrO3 have the worst symmetry among these phosphors. Furthermore, CaZrO3:Eu exhibit the strongest luminescent intensity and pure red color which show that this phosphors may be more possible to be regarded as a promising candidate for applications in displays. (C) 2007 Elsevier B.V. All rights reserved.