Lead zirconate titanate (PZT) thin films with a composition near the morphotropic phase boundary region were deposited onto Pt(111)/Ti/SiO2/Si(100) substrates using a sol-gel method. A seeding layer was introduced between the most underlying surface of the PZT film and the platinum electrode surface to control the texture of the PZT thin film. The lead oxide seeding layer resulted in the formation of a single-phase perovskite and absolutely (100)-textured PZT film. SEM, XRD, XPS, and AES were used to characterize the evolution of the lead oxide layer and the PZT thin films. The growth kinetic mechanism of the (100)-textured PZT thin films was proposed phenomenologically. The ferroelectric and piezoelectric properties of the PZT films were also evaluated and discussed in association with different preferential orientations.

Thermoelectric microgenerators and microcoolers are becoming technologically important for microelectromechanical systems (MEMS), but the conventional cutting and assembling techniques have limitation in miniaturizing the dimensions of thermoelectric devices to the micrometer order. We have combined MEMS technology and materials processing into a novel process to manufacture thermoelectric micro-modules with densely aligned fine-scale and high-aspect-ratio P-N elements. Our process consists of the following major steps: (1) micromachining a silicon mold; (2) filling the mold with thermoelectric materials; (3) connecting P-and N-type elements and assembling the whole module. By using the present process, Bi-Sb-Te system thermoelectric elements of 300m height and 40m cross-sectional width can be fabricated successfully.

Dense polycrystalline Ti3SiC2 samples were fabricated by reactively hot-isostatic pressing (HIPing) a mixture of elemental Ti, Si and C powders. The mechanical properties, including load-strain response, bending strength, fracture toughness and crack propagation, were investigated from ambient temperature to 1573 K. Non-linear stress-strain responses were observed in the polycrystalline Ti3SiC2 materials at ambient temperature. It is conceivable that the inelastic deformation is attributable to micro-deformations that consist of slip between micro-lamellae within individual grains and the formation of microcracks between grains. The polycrystalline Ti3SiC2 exhibited a brittle-to-ductile transition at about 1473K; above this the Ti3SiC2 samples deformed plastically and exhibited high strains (>1.5%), whereas below 1373K only limited inelastic deformation was observed prior to fracture. The mode I fracture toughness, KIC, was measured by the single-edge notched beam (SENB) method to be 4.52MPa m1/2 at ambient temperature. Both fracture strength and fracture toughness decrease only slightly with increasing temperature up to 1273K, above which they decrease more rapidly and reach half of their room-temperature values by 1473K.

Porous ceramics of lead zirconate titanate (PZT) were prepared by sintering powder compacts consisting of PZT and stearic acid powders in an air atmosphere; stearic acid was added as a pore-forming agent (PFA). The dielectric, elastic and piezoelectric properties of uniformly porous PZT ceramics were investigated as a function of the porosity volume fraction. Furthermore, a beam-shaped PZT actuator sample with a graded porosity content across its thickness was fabricated by sintering PFA-graded powder compacts. The electric-fieldinduced bending displacement characteristics of the actuator samples were measured by using strain gauges and were found to be in good agreement with the theoretical predication based on a classical lamination theory.