相关论文: Polarization fields in nitride nanostructures: the…
A nanocomposite film containing highly polarizable inclusions in a fluid background is explored when an external electric field is applied perpendicular to the planar film. For small electric fields, the induced dipole moments of the…
Nanoscale polar structures are significant for understanding polarization processes in low-dimensional systems and hold potential for developing high-performance electronics. Here, we demonstrate a polar vortex superstructure arising from…
We give detailed analysis of the effect of depolarizing field in nanometer-size ferroelectric capacitors studied by Kim et al. [Phys. Rev. Lett. 95, 237602 (2005)]. We calculate a critical thickness of the homogeneous state and its…
A reduction of polarization in ultra-thin ferroelectric films appears to be fundamental to ferroelectricity at the nanoscale. For the model system PbTiO3 on SrTiO3, we report observation of the polarization vs. thickness relation. Distinct…
Accurate values for polarization discontinuities between pyroelectric materials are critical for understanding and designing the electronic properties of heterostructures. For wurtzite materials, the zincblende structure has been used in…
In this paper we study the size effects of the ferroelectric nanotube and nanowire phase diagrams and polar properties allowing for radial stress and depolarization field influence. The approximate analytical expression for the…
We study the dependence of macroscopic polarization on composition and strain in wurtzite III-V nitride ternary alloys using ab initio density-functional techniques. The spontaneous polarization is characterized by a large bowing, strongly…
Pressure-induced polarization switching in ferroelectric thin films has emerged as a powerful method for domain patterning, allowing to create predefined domain patterns on free surfaces and under thin conductive top electrodes. However,…
The large electronic polarization in III-V nitrides allow for novel physics not possible in other semiconductor families. In this work, interband Zener tunneling in wide-bandgap GaN heterojunctions is demonstrated by using…
The free-carrier screening of macroscopic polarization fields in wurtzite GaN/InGaN quantum wells lasers is investigated via a self-consistent tight-binding approach. We show that the high carrier concentrations found experimentally in…
We present the concept and experimental realization of polarization-induced bulk electron doping in III-V nitride semiconductors. By exploiting the large polarization charges in the III-V nitrides, we are able to create wide slabs of high…
Thin films of aluminum hafnium nitride (Al$_{1-x}$Hf$_{x}$N) were synthesized via reactive magnetron sputtering for Hf contents up to $x$ = 0.13. X-ray diffraction showed a single $c$-axis oriented wurtzite phase for all films. Hard X-ray…
Ab initio calculations of the spontaneous polarization and piezoelectric properties of boron nitride nanotubes show that they are excellent piezoelectric systems with response values larger than those of piezoelectric polymers. The…
We propose a concept for superconducting electric field-effect devices based on superconducting films sandwiched between ferroelectric layers. We provide theoretical calculations that indicate how the field effect in these devices could be…
The discovery of ferroelectricity in AlScN allowed the first clear observation of the effect in the wurtzite crystal structure, resulting in a material with a previously unprecedented combination of very large coercive fields (2-5 MV/cm)…
The symmetry breaking inevitably present in the vicinity of any surface, namely an inversion center disappears in surface normal direction and only axes and planes normal to the surface conserve, gives rise to the spontaneous piezomagnetic,…
Using Landau-Ginzburg-Devonshire approach we calculated the equilibrium distributions of electric field, polarization and space charge in the ferroelectric-semiconductor heterostructures containing proper or incipient ferroelectric thin…
A common scenario of magnetoelectric coupling in multiferroics is the electric polarization induced by spatially modulated spin structures. It is shown in this paper that the same mechanism works in magnetic dielectrics with inhomogeneous…
Weakly coupled ferroelectric/dielectric superlattice thin film heterostructures exhibit complex nanoscale polarization configurations that arise from a balance of competing electrostatic, elastic, and domain-wall contributions to the free…
The wurtzite structure is one of the most frequently found crystal structures in modern semiconductors and its inherent spontaneous polarization is a defining materials property. Despite this significance, confusion has been rampant in the…