The problem with doorknobs and other ceramics?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Mddeming-at-aol-dot-com 

I came across an article from >40 years ago that explains why some ceramic 
capacitors are so poor for TC work. .

Snip+++
"The rather recent development of ferroelectric solids such as 
barium-titanate ceramic provides another way of greatly increasing 
capacitance. The name comes from the fact that these materials have 
electrical properties analogous to the magnetic properties of ferromagnetic 
materials. They can be permanently electrified, exhibit electrical 
hysteresis, and have extremely high dielectric constants. For example, the 
Ba-Ti ceramic has a
dielectric constant of over 1400. The electrical hysteresis, however, could 
cause extensive heating if used if High power, high frequency applications, 
as some power would need to be dissipated to achieve each reversal of 
polarity."

Snip+++
Embarrassingly, the article was one on dielectrics that I had submitted for 
our H. S. Physics Club magazine.

Matt D.