Quantum mechanics

Magnetic field

Pure mathematics

Magnetization

Biology

Materials science

Coercivity

Field (mathematics)

Domain wall (magnetism)

Electric field

Ferroelectricity

Physical chemistry

Polarization (electrochemistry)

Physics

Dielectric

Mathematics

Depolarization

Condensed matter physics

Chemistry

Biophysics

Optoelectronics

Nature Communications

Depolarization in ferroelectric materials has been studied since the 1970s, albeit quasi-statically. The dynamics are described by the empirical Merz law, which gives the polarization switching time as a function of electric field, normalized to the so-called activation field. The Merz law has been used for decades; its origin as domain-wall depinning has recently been corroborated by molecular dynamics simulations. Here we experimentally investigate domain-wall depinning by measuring the dynamics of depolarization. We find that the boundary between thermodynamically stable and depolarizing regimes can be described by a single constant, P r / ε 0 ε ferro E c . Among different multidomain ferroelectric materials the values of coercive field, E c , dielectric constant, ε ferro , and remanent polarization, P r , vary by orders of magnitude; the value for P r / ε 0 ε ferro E c however is comparable, about 15. Using this extracted universal value, we show that the depolarization field is similar to the activation field, which corresponds to the transition from creep to domain-wall flow.

Depolarization of multidomain ferroelectric materials