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We investigated the effect of internal electrode composition on the co-firing behavior of (K0.47Na0.51Li0.02) (Nb0.8Ta0.2)O3 (KNLNT) lead-free multilayer ceramic actuators using AgPd-KNLNT inner electrodes. KNLNT/AgPd-KNLNT multilayer laminates were fabricated using tape casting, and then co-fired at 1050°C for 4 h. Co-fired AgPd-KNLNT composite electrodes revealed ‘3-0’ connectivity without formation of any secondary phase and resulting in the reduced thermal mismatch between piezoceramic and electrode layers on firing cycles. [ABSTRACT FROM PUBLISHER]

To achieve cost reduction in multi-layer ceramic capacitors and actuators, which use a silver-palladium alloy as internal electrode, the trend is to use alloys with the highest silver content possible. This requires ceramic materials which must be sintered at a relative low temperature. Goal is to avoid much diffusion of silver into the ceramics. Analysis of the composition of the electrode in multilayer components is a good tool to investigate the diffusion of silver during sintering. Analysis of various multi-layer components with different silver-palladium alloys shows that the diffusion of silver during sintering is dependent on the difference between the sintering temperature of the multilayer component and the melting point of the silver-palladium alloy used. Diffusion of silver into the ceramics during sintering is negligible when this difference is at least 100 °C. [ABSTRACT FROM AUTHOR]

Nano-sized silver-palladium co-powder has been synthesized from silver nitrate-palladium chloride by wet chemical method. The present experimental conditions are applied for the first time for Ag-Pd co-powders wherein sodium formaldehyde sulfoxylate (SFS) has been used as an external reducing agent to simultaneously reduce respective metal salts. SFS reduces the metal salts at room temperature thus prevents formation of bigger particles of the respective metals in co-powder. Powder X-ray diffraction measurements (XRD) and Transmission electron microscopy (TEM) suggest the formation of nano-sized Ag-Pd co-powder with particle diameter in the range of about 25 nm. SEM shows that the powder morphology changes with temperature. Heat treatment of 90:10 (Ag:Pd) composition showed shift in XRD peaks indicating alloy formation of Ag/Pd at lower temperature. Thick-films generated by use of the co-powder resulted in Ag/Pd alloy at about 500°C as confirmed by the XRD. Thermal analysis showed that Ag/Pd co-powders initially gain the weight due to oxidation followed by the weight loss. [ABSTRACT FROM AUTHOR]