A promising way to improve the performance of piezoelectric ceramics is grain orientation by templated grain growth. In this work lead‐based piezoelectric ceramics Pb(Mg1/3Nb2/3)0.68Ti0.32O3 (PMN–32PT) and Pb(Mg1/3Nb2/3)0.42(Ti0.638Zr0.362)0.58O3 (PMN–37PT–21PZ) ceramics were textured via templated grain growth process. For texturization (001)‐oriented BaTiO3 (BT) platelets (approximately 10 μm × 10 μm × 2 μm) were utilized as templates. The texturized ceramics were accomplished by aligning the templates by tape casting. The template growth into the matrix resulted in textured ceramics with Lotgering factors between 0.94 and 0.99 for both compositions. Consequences of the texture are enhanced dielectric and piezoelectric properties. Unipolar strain‐field measurements of textured ceramics showed 0.25% strain s33 at 3 kV/mm. Large signal d33* of up to 878 pm/V were determined directly from strain measurements. Compared with randomly oriented ceramics in texturized samples unipolar strain s33 and large signal d33* was enhanced by a factor of up to 1.8.

Relaxor ferroelectrics near the morphotropic phase boundary were prepared by pressureless sintering at various temperatures in order to study the influence of grain size on phase composition and electrical properties. Investigations of the microstructure indicate an increase in grain size from 0.5to3.7μm when the sintering temperature is increased from 1050to1290°C. The corresponding phase composition is changed from predominantly rhombohedral for small grain sizes to more than 80% tetragonal for larger grain sizes. Low-voltage measurements of poled and unpoled samples correlate well with the x-ray diffraction results. An increase of the permittivity after poling is found for samples with a high tetragonal phase content, while samples with a predominantly rhombohedral composition show a slight decrease. The remanent polarization as well as uni- and bipolar strain increase with increasing sintering temperature by a factor larger than 2, whereas the coercive field EC remains nearly constant for all sintering conditions.

Based on the planar SOFC and SOE technology, a high temperature metal – air battery was operated at temperatures between 700°C and 800°C. It reached charging and discharging capacities of about 2 hours at power densities of more than 250mW/cm². A Siemens stack concept was developed and validated in numerous lab experiments as well as in several stack demonstrators of more than 1kW power output. The storage material is a proprietary development consisting of a iron/iron oxide combination which can be produced economically. It showed very low degradation rates of 1 - 2% in 1,000 charging / discharging cycles. More than 10,000 cycles were reached in 10x10 cm² short stacks. System efficiencies for the upper MW range of > 60% and a cycle life of about 10,000 cycles will be achieved.

Cofired multilayer piezoceramic actuators as extremely fast valve driving elements will lead to a significant progress in the field of fuel injection systems. A careful adaptation of the component performance to the system demands, an extraordinary high reliability, and competitive low production costs are prerequisites for this large-scale industrial application.With proper material selection as basis, conventional multilayer technology has to he substantially extended in order to achieve large stack volumes, to avoid degradation effects during cofiring and nevertheless to meet the target costs. Under large-signal driving conditions, the static and dynamic behavior of the component is essentially influenced by driving pulse shape. clamping force, and stiffness of the load. Linear FE (Finite Element) methods arc employed to calculate the performance criteria of different actuator designs. Moreover, a FE-implementation using a micromechanical domain switching model was developed in order to describe the strongly nonlinear material behavior. Together with an quantitative estimation of crack initiation and propagation by means of fracture mechanics, these methods can give valuable hints for controlling the effects of fatigue and deterioration which may limit the operating life time.In order to optimize the interaction of the electrical and mechanical parts in the injection system, dynaniic models of pie7oelectric components must he provided. A nonlinear model of the stack actuator has been developed for the analysis software MATLAB/SIMULINK. Special attention has been paid to the hysteresis properties.

Properties of Li- and Ta- modified (K,Na)NbO3 piezoceramics with the base composition near the orthorhombic-tetragonal phase boundary have been investigated with respect to variation of temperature, stoichiometry, compositional homogeneity, atmosphere of thermal treatment, and dopants (Ba, Mn). Although the influence of the most of the abovementioned factors has already been reported in the literature, the paper focuses on several aspects of the composition—property relationships that still remain controversial or poorly elucidated. In particular, we show that improvement of compositional homogeniety in these ceramics emphasizes the instability of piezoelectric response with respect to variation of temperature in the vicinity of the orthorhombic-tetragonal phase transition. Ba dopant is shown to suppress conductivity in ceramics sintered in air, though it makes conductivity more sensitive to variation of the oxygen partial pressure. Mn dopant is shown to suppress conductivity and strongly reduce the influence of the oxygen partial pressure on conductivity of the ceramics. Finally, we show that chemical modifications to the ceramic composition, such as Mn dopant or variation of nonstoichiometry affect the piezoelectric response mainly by the shift of the orthorhombic-tetragonal phase transition temperature.