Hexagonal ABC semiconductors as ferroelectrics.

Hyperferroelectrics: proper ferroelectrics with persistent polarization.

All known proper ferroelectrics are unable to polarize normal to a surface or interface if the resulting depolarization field is unscreened, but there is no fundamental principle that enforces this behavior. In this work, we introduce hyperferroelectrics, a new class of proper ferroelectrics which polarize even when the depolarization field is unscreened, this condition being equivalent to inst...

Compositionally graded ferroelectrics as wide band gap semiconductors: Electrical domain structures and the origin of low dielectric loss

Functional materials with compositional gradients exhibit unique characteristics that are different from the components comprising the structure. Graded ferroelectrics are very good examples to such materials where a systematic variation in composition is introduced along the thickness of a thin film heterostructure. Such structures display interesting properties including the disappearance of ...

Degenerate Four-wave Mixing in Semiconductors and Ferroelectrics

Ferroelectric electron holography.

Ferroelectrics are increasingly important as materials in semiconductor technology, e.g. for building non-volatile memory chips. For optimisation of the properties of such devices, there is an urgent need for methods, which analyse the ferroelectric properties at nanometer scale. Furthermore, the basic understanding of the interaction of ferroelectrics with electrons in the transmission electro...

ABC Ferroelectrics as Novel Materials for Phononic Crystals

In the present work the acoustic band structure of a two-dimensional (2D) phononic crystal (PC) containing an semiconducting ferroelectrics ABC (A=Sb, Bi; B=S, Se, Te; C=I, Br, and Cl) were investigated theoretically and numerically by the plane-waveexpansion (PWE) method. Two-dimensional PC with square lattices composed of semiconducting ferroelectric cylindrical rods embedded in the organic/i...