  We developed a model with no adjustable parameter for retention loss at short
and long time scale in ferroelectric thin-film capacitors. We found that the
predictions of this model are in good agreement with the experimental
observations in the literature. In particular, it explains why a power-law
function shows better fitting than a linear-log relation on a short time scale
(10^-7 s to 1 s) and why a stretched exponential relation gives more precise
description than a linear-log plot on a long time scale (>100 s), as reported
by many researchers in the past. More severe retention losses at higher
temperatures and in thinner films have also been correctly predicted by the
present theory.
