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Inner Electrodes (inner + electrode)

Distribution by Scientific Domains
Polymers and Materials Science100%

Selected Abstracts

Inner Electrodes for Multilayer Varistors

INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 2 2009
Shu-Ting Kuo
In the present study, Pt or AgPd metal is used as the inner electrode for Bi2O3 -doped ZnO multilayer varistors (MLV). The growth of the ZnO grains is constrained by the presence of the inner electrodes. The Pt inner electrodes are chemically inert to Bi2O3 -doped ZnO. The Bi2O3 could react with Pd to form PdBi2O4. The Bi2O3 -rich liquid also tends to wet the AgPd electrode. The size of ZnO grains in the MLV/AgPd specimen is larger. The ZnO grains in the MLV/AgPd specimen can even grow to a size larger than the layer thickness at the expense of electrode continuity. [source]

The Chemical Interaction of Silver,Palladium Alloy Electrodes with Bismuth-Based Piezomaterials

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 4 2010
Denis Schuetz
Multilayer technology relies heavily on the chemical compatibility of metal and ceramic. This work focuses on the ceramic,electrode interaction between 92Bi0.5Na0.5TiO3,6 BaTiO3,2K0.5Na0.5NbO3 [(Bi0.46Na0.47Ba0.06K0.01)(Nb0.02Ti0.98)O3], a promising actuator material and forerunner to an emerging class of lead-free actuator materials, and a silver,palladium alloy for inner electrodes, the only currently viable material for the firing temperatures necessary (1100°C). Of special concern was the high content of bismuth in the ceramic since prior investigations suggest that Bi2O3 (as well as various bismuth titanates) used as a fluxor in electroceramics are prone to forming the intermediate-phase bismuth palladate (Bi2PdO4), which can lead to poor contacting and delamination of multilayer stacks. Remarkably, no evidence of bismuth palladate formation could be found. However, the phase relations of the bulk ceramic have proven to be quite complex. Potassium was being drained out of the bulk ceramic either constituting the secondary phase K4Na2(TiO3)3 in unmodified experiments or evaporating and being replaced by silver in samples in contact with Ag. Mechanisms for the formation of these phases or the lack thereof are proposed. These findings were obtained by XRD, TG-DSC, and SEM with EDX, and LA-ICPMS. [source]

Effects of Calcination Temperature and A/B Ratio on the Dielectric Properties of (Ba,Ca)(Ti,Zr,Mn)O3 for Multilayer Ceramic Capacitors with Nickel Electrodes

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 6 2000
Wen-Hsi Lee
The electrical performance of multilayer ceramic capacitors (MLCCs) with Ni inner electrodes, made from (Ba,Ca)(Ti,Zr,Mn)O3 (BCTZM), is closely related to the calcination temperature and the A/B ratio of the powder. For materials showing A/B = 1.000, the lifetime, the breakdown voltage, and the RC increase with higher calcination temperatures. No significant effect of the calcination temperature on RC and lifetime was found for materials showing A/B = 0.991. The isoelectric point of BCTZM is shifted toward higher pH values when the calcination temperature is decreased. The above results are attributed to the colloidal stability of aqueous BCTZM suspensions and the resulting green density of powder compacts. [source]