Polarization switching dynamics governed by the thermodynamic nucleation process in ultrathin ferroelectric films.
In most ferroelectrics, the domain nucleation barrier (U*) is thermally insurmountable; this is called "Landauer's paradox." However, we showed that, in ultrathin films, the large depolarization fields could lower U* to a level comparable to thermal energy (k(B)T), resulting in power-law decay of polarization. We empirically found a universal relation between the power-law decay exponent and U*/k(B)T. This relation will provide a practical but fundamental limit for capacitor-type ferroelectric devices, analogous to the superparamagnetic limit for magnetic memory devices.
Jo
J Y
JY
FPRD, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea.
Kim
D J
DJ
Kim
Y S
YS
Choe
S-B
SB
Song
T K
TK
Yoon
J-G
JG
Noh
T W
TW