Electronic Structure and Ferroelectricity in Srbi 2 Ta 2 O 9

Structure of post - annealed ferroelectric PbZr Ti O and SrBi Ta O thin x 1 – x 3 2 2 9 films

In order to fabricate good quality ferroelectric thin films, PbZr Ti O (PZT) and SrBi Ta O (SBT) films were fabricated x 1–x 3 2 2 9 ( ) on SiO ySi(100) substrates and on PtyTiy SiO ySi(100) substrates by pulsed laser excimer deposition (PLD). X-ray diffraction, 2 2 Rutherford backscattering analysis, and atomic force microscopy were used to characterize the structural properties of the samples...

Variations of differential capacitance in SrBi 2 Ta 2 O 9 ferroelectric films induced by photoperturbation

Nanostructure patterns of piezoelectric and ferroelectric complex oxides with various shapes, obtained by natural lithography and pulsed laser deposition.

A variety of patterns of well-ordered perovskite-type complex oxide nanostructures were obtained by pulsed laser deposition (PLD) on conductive single crystalline substrates through latex sphere monolayer and double-layer masks. Patterns obtained via deposition through hexagonally close packed (hcp) latex sphere monolayers include the usual arrays of hexagonally ordered nanoislands, hexagonal a...

Recent Progress of Ferroelectric-Gate Field-Effect Transistors and Applications to Nonvolatile Logic and FeNAND Flash Memory

We have investigated ferroelectric-gate field-effect transistors (FeFETs) with Pt/SrBi₂Ta₂O₉/(HfO₂)x(Al₂O₃)1-x (Hf-Al-O) and Pt/SrBi₂Ta₂O₉/HfO₂ gate stacks. The fabricated FeFETs have excellent data retention characteristics: The drain current ratio between the on- and off-states of a FeFET was more than 2 × 10⁶ after 12 days, and the decreasing rate of this ratio was so small that the extrapol...

Ferroelectricity driven by the noncentrosymmetric magnetic ordering in multiferroic TbMn(2)O(5): a first-principles study.

The ground state structural, electronic, and magnetic properties of multiferroic TbMn(2)O(5) are investigated via first-principles calculations. We show that the ferroelectricity in TbMn(2)O(5) is driven by the noncentrosymmetric magnetic ordering, without invoking the spin-orbit coupling and noncollinear spins. The intrinsic electric polarization in this compound is calculated to be 1187 nC cm...