SEARCH · Search NASA
Results for “FERROELECTRICS”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Ab initio elasticity at finite temperature and stress in ferroelectrics
Not Available
Understanding and controlling dipolar Moiré pattern in ferroelectric perovskite oxide nanolayers
Not Available
Enhanced Thermal Hall Effect in Nearly Ferroelectric Insulators
In the context of recent experimental observations of an unexpectedly large thermal Hall conductivity, $κ_H$, in insulating $La_2CuO_4$ (LCO) and $SrTiO_3$ (STO), in this paper we theoretically explore conditions under which acoustic phonons can give rise to such a large $κ_H$. Both the intrinsic and extrinsic contributions to $κ_H$ are large in proportion to the dielectric constant, $ε$, and the “flexoelectric” coupling, $F$. While the intrinsic contribution is still orders of magnitude smaller than the observed effect, an extrinsic contribution proportional to the phonon mean-free path appears likely to account for the observations, at least in STO. We predict a larger intrinsic $κ_H$ in certain insulating perovskites.
Giant negative electrostriction and dielectric tunability in a van derWaals layered ferroelectric
Abstract not provided
Rhombohedral distortion and percolation phenomena in B-site substituted perovskite ferroelectrics wi
Explore the source record for details and available documents.
Behavior of strain stripe networks in barium titanate nanocrystals on crossing its ferroelectric phase transition
Nanoscale strain networks are reported in BaTi O 3 (BTO) crystals of 300 nm size using Bragg coherent diffractive imaging. BTO nanocrystals with clear facets were chosen to identify the crystallographic directions, allowing the strain field direction and periodicity to be studied in detail. Stripes of strain were observed, which were both stable and preserved in tetragonal and cubic phases at elevated temperatures, above the tetragonal-to-cubic phase transition. A finite element analysis approach was used to simulate the domain structures inside a BTO crystal and to understand the origins of the strain stripes as piezoelectric blocks. A 180 ∘ domain model gives a better qualitative match to the experimental images. Published by the American Physical Society 2024
Domain wall mobility and roughening in doped ferroelectric hexagonal manganites
Not Available
Strain-driven autonomous control of cation distribution for artificial ferroelectrics
Strain provides autonomous control of atomic building blocks for the synthesis of functional materials.
Piezoresponse force spectroscopy on a ferroelectric PbTiO3 thin film
A grid spectroscopy measurement performed on a 200nm PbTiO3 thin film to acquire local piezoresponse hysteresis loops. This dataset is associated with the 2021 Smoky Mountains Data Challenge.
Electric field effect on lattice dynamics of a relaxor ferroelectric PMN-30PT measured on ARCS.
The combined inelastic neutron scattering data from ARCS for poled PMN-30PT single crystal is at 300K and for unpoled crystal the data were collected at 300K and at 488K. The incident neutron energy for both poled and unpoled crystals was 25 meV . To obtain a significant four-dimensional Q-E volume, the crystal was rotated with steps of 0.5 degree in the beam. All individual angles were combined using HORACE software package (https://pace-neutrons.github.io/Horace/unstable/user_guide/Getting_started.html) to generate these sqw files. The file labeled PMN_PT_poled_new.sqw is for poled crystal and files labeled PMN_PT_300K.sqw and PMN_PT_488K.sqw are for unpoled crystal at 300K and 488K respectively.
Machine-learning enabled construction of temperature-strain phase diagrams of ferroelectric thin films
Not provided.
Fast Electrically-Controlled Ferroelectric Tuners for RF Cavities
Fast electrically-controlled tuners for RF cavities are proposed. Their usefulness for efficient RF manipulation and technical details are discussed.
Manufacturing of Ferroelectric Material Under a Quality Management System.
Abstract not provided.
Simulating Nonlinear Domain Reorientation and Phase Transformation Phenomena in a Micromechanical Ferroelectric Model.
Abstract not provided.
Anisotropic Extension of a Model for Materials with Ferroelectric to Antiferroelectric Phase Transformation.
Abstract not provided.