2 research outputs found
What Determines the Critical Electric Field of AFE-to-FE in Pb(Zr,Sn,Ti)O<sub>3</sub>‑Based Perovskites?
Electric-field-induced antiferroelectric-ferroelectric
(AFE-FE)
phase transition is a prominent feature of antiferroelectric (AFE)
materials. The critical electric field of this phase transition is
crucial for the device performance of AEFs in many applications, but
the determining factor of the critical electric field is still unclear.
Here, we have established the correlation between the underlying structure
and the critical electric field by using in situ synchrotron
X-ray diffraction and high-resolution neutron diffraction in Pb(Zr,Sn,Ti)O3-based antiferroelectrics. It is found that the critical electric
field is determined by the angle between the average polarization
vector in the incommensurate AFE state and the [111]P polarization
direction in the rhombohedral FE state. A large polarization rotation
angle gives rise to a large critical electric field. Further, density
functional theory (DFT) calculations corroborate that the lower energy
is required for driving a smaller angle polarization rotation. Our
discovery will offer guidance to optimize the performance of AFE materials
Emergent Three-Dimensional Electric Dipole Sinewave in Bulk Perovskite Oxides
The magnetic and electric dipoles of ferroics play a
central role
in their fascinating properties. In particular, topological configurations
have shown promising potential for use in novel electromechanical
and electronic devices. Magnetic configurations from simple collinear
to complex topological are well-documented. In contrast, many complex
topological features in the electric counterpart remain unexplored.
Here, we report the first example of three-dimensional electric dipole
sinewave topological structure in a PbZrO3-based bulk perovskite,
which presents an interesting triple-hysteresis loop macroscopically.
This polar configuration consists of two orthogonal sinewave electric
dipole modulations decoded from a polar incommensurate phase by advanced
diffraction and atomic-resolution imaging techniques. The resulting
topology is unraveled to be the competition between the antiferroelectric
and ferroelectric states, stabilized by the modulation of the Pb 6s2 lone pair and the antiferrodistortive effect. These findings
further reinforce the similarity of the magnetic and electric topologies