Related papers: Defect ordering and defect-domain wall interaction…
We report a theoretical investigation of a charged 180$^\circ$ domain wall in ferroelectric PbTiO$_3$, compensated by randomly distributed immobile charge defects. For this we utilize atomistic shell-model simulations and continuous…
Free electrons can screen out long-range Coulomb interaction and destroy the polar distortion in some ferroelectric materials, whereas the coexistence of polar distortion and metallicity were found in several non-central-symmetric metals…
Ferroelectric materials are characterized by degenerate ground states with multiple polarization directions. In a ferroelectric capacitor this should manifest as equally favourable up and down polarization states. However, this ideal…
Perovskite nitrides are starting to be explored for their promising properties distinct from their oxide counterparts. Here, through first-principles density functional computations, we study the intricate relationship between…
By performing first-principles calculations on four capacitor structures based on BaTiO3 and PbTiO3, we determine the intrinsic interfacial effects that are responsible for the destabilization of the polar state in thin-film ferroelectric…
Polar metals characterized by the simultaneous coexistence of ferroelectric distortions and metallicity have attracted tremendous attention. Developing such materials at low dimensions remains challenging since both conducting electrons and…
The full phonon dispersion relations of lead titanate and lead zirconate in the cubic perovskite structure are computed using first-principles variational density-functional perturbation theory, with ab initio pseudopotentials and a…
The structure of the ferroelectric phase of undoped KTiOPO$_4$ and its solid solutions with zirconium and niobium is studied from first principles within the density functional theory. The second-order nonlinear susceptibility tensor and…
Strontium titanate (SrTiO$_3$), famously described by Nobel laureate K. A. M\"uller as the "drosophila of solid-state physics", has been extensively investigated over the last seventy five years for its intricate coupling of structural,…
The effect of Sr doping in BaTiO3 (BTO) with nominal compositions Ba0.80Sr0.20TiO3 (BSTO) have been explored in its structural, lattice vibration, dielectric, ferroelectric and electrocaloric properties. The temperature dependent dielectric…
Interface effects on the ferroelectric behavior of PbTiO$_3$ ultrathin films deposited on SrTiO$_3$ substrate are investigated using an interatomic potential approach with parameters fitted to first-principles calculations. We find that the…
First-principles calculations are performed to investigate alloying and ferroelectric effects in lead zirconate titanate (PZT) with high Ti composition. We find that the main effect of alloying in the paraelectric phase of PZT is the…
The nature of the often reported room temperature ferromagnetism in transition metal doped oxides is still a matter of huge debate. Herein we report on room temperature ferromagnetism in high quality Co-doped ZnO (Zn1-xCoxO) bulk samples…
Structural and magnetic properties of the doped terbium manganites (Tb,A)MnO3 (A = Gd, Dy and Ho) have been investigated using first-principles calculations and further confirmed by subse- quent experimental studies. Both computational and…
Rare-earth doped barium zirconate (BaZrO$_3$) ceramics are of interest as proton-conducting and luminescent materials. Here, we report a study of dysprosium (Dy) and other relevant point defects in BaZrO$_3$ using hybrid density-functional…
Intertwined orders refer to strongly coupled and mutually dependent orders that coexist in correlated electron systems, often underpinning key physical properties of the host materials. Among them, polar, chiral, and ferro-rotational orders…
Modifying the optoelectronic properties of nanostructured materials through introduction of dopant atoms has attracted intense interest. Nevertheless, the approaches employed are often trial and error, preventing rational design. We…
SrTiO$_{3}$ is an incipient ferroelectric and an exceptionally dilute superconductor with a dome-like dependence on carrier concentration. Stabilization of a polar phase through chemical substitution or strain significantly enhances the…
The $\phi(\kpp)\sim \kpp$ relation is called polarization structure. By density functional calculations, we study the polarization structure in ferroelectric perovskite PbTiO$_3$, revealing (1) the $\kpp$ point that contributes most to the…
Lead titanate (PbTiO3) is a classical example of a ferroelectric perovskite oxide illustrating a displacive phase transition accompanied by a softening of a symmetry-breaking mode. The underlying assumption justifying the soft-mode theory…