Abstract
In this letter, the authors report on the giant dielectric constant properties in a hitherto unexplored material, the superionic conductor lead tin fluoride
Pb
Sn
F
4
. Despite its superionic behavior,
Pb
Sn
F
4
is surprisingly found to exhibit extraordinary high dielectric constant
(
ε
′
∼
10
5
)
.
ε
′
is almost independent of temperature and frequency over wide ranges. The authors find that the high value of
ε
′
originates from an internal effect, such as internal barrier layer capacitor, rather than from a surface barrier layer capacitor formed at the electrode/sample interface.