ac breakdown characteristics of ceramic materials

Abstract

ac breakdown properties of alumina, aluminum nitride, and glass ceramic (Si02-Al,03-MgO-Ti02) materials have been investigated. The breakdown strength of glass ceramics ( -65 kV/mm) was found to be higher than that of alumina ( -31 kV/mm) and aluminum nitride ( -16 kV/mm). The specimens were characterized for their density, porosity, and microstructural parameters, such as grain size and distribution, as they are believed to influence the breakdown properties significantly. In all the cases, the prebreakdown and breakdown conduction were found to be associated with visible-light emission at the electrode-specimen interface. The samples that underwent breakdown were found to exhibit irregular puncture channel, terminated with craters at both ends. Several types of crystallization structures were observed at the rim of the craters and in some cases at the edges of the breakdown channels. It is suggested that the breakdown process of the ceramic materials is a combination of electronic, electromechanical, and thermal processes.

Contribution to the understanding of the relationship between mechanical and dielectric strengths of Alumina

“…This has been precisely verified using a chemical analysis (ESD). 7 In single crystal Alumina (Sapphire), cleavage planes are clearly visible after dielectric breakdown tests. In Fig.…”

“…These observations are in good agreement with previous works. 4,7,8 A statistical analysis has shown that the size of the crater is much more important on one of the channel terminations. 5 On most of the samples, only one crater can be distinguished (i.e.…”

A systematic study on structural and dielectric properties of lead zirconate titanate/(Pb,La)(Zr(1−x)Ti(x))O3 thin films deposited by metallo-organic decomposition technology

“…It is known that the trans-grainar cracks may provide a low dielectric pass, thus causing the easy dielectric breakdown. 46,47 The resistance degradation was discussed by Klee and his co-workers, and they concluded that in PZT thin films, the resistance degradation was mainly caused by the charge transport along the grain boundaries instead of the ionic transport in the bulk of grains. 47…”

Flexible antiferroelectric thick film deposited on nickel foils for high energy‐storage capacitor

“…The fine grains distribute around the large grains and their size is order of magnitude smaller than that of the large grains (~140 nm). The formation of fine grains significantly increases the density of thick films, which plays a positive role in enhancing the BDS and improving of the energy‐storage properties . Figure C shows the Pb, La, Zr, and Ti element mappings of the surface of the PLZT film.…”