Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Ferroelectric Sm-doped BiMnO3 thin films with ferromagnetic transition temperature enhanced to 140 K.

ABSTRACT: A combined chemical pressure and substrate biaxial pressure crystal engineering approach was demonstrated for producing highly epitaxial Sm-doped BiMnO(3) (BSMO) films on SrTiO(3) single crystal substrates, with enhanced magnetic transition temperatures, TC up to as high as 140 K, 40 K higher than that for standard BiMnO(3) (BMO) films. Strong room temperature ferroelectricity with piezoresponse amplitude, d(33) = 10 pm/V, and long-term retention of polarization were also observed. Furthermore, the BSMO films were much easier to grow than pure BMO films, with excellent phase purity over a wide growth window. The work represents a very effective way to independently control strain in-plane and out-of-plane, which is important not just for BMO but for controlling the properties of many other strongly correlated oxides.

SUBMITTER: Choi EM

PROVIDER: S-EPMC4176521 | biostudies-other | 2014 Sep

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Temperature-dependent infrared ellipsometry of Mo-doped VO2 thin films across the insulator to metal transition.

Project description:We present a spectroscopic ellipsometry study of Mo-doped VO2 thin films deposited on silicon substrates for the mid-infrared range. The dielectric functions and conductivity were extracted from analytical fittings of ? and ? ellipsometric angles showing a strong dependence on the dopant concentration and the temperature. Insulator-to-metal transition (IMT) temperature is found to decrease linearly with increasing doping level. A correction to the classical Drude model (termed Drude-Smith) has been shown to provide excellent fits to the experimental measurements of dielectric constants of doped/undoped films and the extracted parameters offer an adequate explanation for the IMT based on the carriers backscattering across the percolation transition. The smoother IMT observed in the hysteresis loops as the doping concentration is increased, is explained by charge density accumulation, which we quantify through the integral of optical conductivity. In addition, we describe the physics behind a localized Fano resonance that has not yet been demonstrated and explained in the literature for doped/undoped VO2 films.

| S-EPMC7244498 | biostudies-literature

Strain-tuned enhancement of ferromagnetic T<sub>C</sub> to 176 K in Sm-doped BiMnO<sub>3</sub> thin films and determination of magnetic phase diagram.

Project description:BiMnO3 is a promising multiferroic material but it's ferromagnetic TC is well below room temperature and the magnetic phase diagram is unknown. In this work, the relationship between magnetic transition temperature (TC) and the substrate induced (pseudo-) tetragonal distortion (ratio of out-of-plane to in-plane lattice parameters, c/a) in BiMnO3 thin films, lightly doped to optimize lattice dimensions, was determined. For c/a > 0.99, hidden antiferromagnetism was revealed and the magnetisation versus temperature curves showed a tail behaviour, whereas for c/a < 0.99 clear ferromagnetism was observed. A peak TC of up to 176 K, more than 70 K higher than for bulk BiMnO3, was achieved through precise strain tuning. The TC was maximised for strong tensile in-plane strain which produced weak octahedral rotations in the out-of-plane direction, an orthorhombic-like structure, and strong ferromagnetic coupling.

| S-EPMC5335565 | biostudies-literature

Solution-processed transparent ferroelectric nylon thin films.

Project description:Ferroelectricity, a bistable ordering of electrical dipoles in a material, is widely used in sensors, actuators, nonlinear optics, and data storage. Traditional ferroelectrics are ceramic based. Ferroelectric polymers are inexpensive lead-free materials that offer unique features such as the freedom of design enabled by chemistry, the facile solution-based low-temperature processing, and mechanical flexibility. Among engineering polymers, odd nylons are ferroelectric. Since the discovery of ferroelectricity in polymers, nearly half a century ago, a solution-processed ferroelectric nylon thin film has not been demonstrated because of the strong tendency of nylon chains to form hydrogen bonds. We show the solution processing of transparent ferroelectric thin film capacitors of odd nylons. The demonstration of ferroelectricity, as well as the way to obtain thin films, makes odd nylons attractive for applications in flexible devices, soft robotics, biomedical devices, and electronic textiles.

| S-EPMC6697430 | biostudies-literature

Interface-induced nonswitchable domains in ferroelectric thin films.

Project description:Engineering domains in ferroelectric thin films is crucial for realizing technological applications including non-volatile data storage and solar energy harvesting. Size and shape of domains strongly depend on the electrical and mechanical boundary conditions. Here we report the origin of nonswitchable polarization under external bias that leads to energetically unfavourable head-to-head domain walls in as-grown epitaxial PbZr(0.2)Ti(0.8)O3 thin films. By mapping electrostatic potentials and electric fields using off-axis electron holography and electron-beam-induced current with in situ electrical biasing in a transmission electron microscope, we show that electronic band bending across film/substrate interfaces locks local polarization direction and further produces unidirectional biasing fields, inducing nonswitchable domains near the interface. Presence of oxygen vacancies near the film surface, as revealed by electron-energy loss spectroscopy, stabilizes the charged domain walls. The formation of charged domain walls and nonswitchable domains reported in this study can be an origin for imprint and retention loss in ferroelectric thin films.

| S-EPMC8491438 | biostudies-literature

Microwave a.c. conductivity of domain walls in ferroelectric thin films.

Project description:Ferroelectric domain walls are of great interest as elementary building blocks for future electronic devices due to their intrinsic few-nanometre width, multifunctional properties and field-controlled topology. To realize the electronic functions, domain walls are required to be electrically conducting and addressable non-destructively. However, these properties have been elusive because conducting walls have to be electrically charged, which makes them unstable and uncommon in ferroelectric materials. Here we reveal that spontaneous and recorded domain walls in thin films of lead zirconate and bismuth ferrite exhibit large conductance at microwave frequencies despite being insulating at d.c. We explain this effect by morphological roughening of the walls and local charges induced by disorder with the overall charge neutrality. a.c. conduction is immune to large contact resistance enabling completely non-destructive walls read-out. This demonstrates a technological potential for harnessing a.c. conduction for oxide electronics and other materials with poor d.c. conduction, particularly at the nanoscale.

| S-EPMC4895023 | biostudies-literature

Atomic-scale engineering of ferroelectric-ferromagnetic interfaces of epitaxial perovskite films for functional properties.

Project description:Besides epitaxial mismatch that can be accommodated by lattice distortions and/or octahedral rotations, ferroelectric-ferromagnetic interfaces are affected by symmetry mismatch and subsequent magnetic ordering. Here, we have investigated La0.67 Sr0.33 MnO3 (LSMO) samples with varying underlying unit cells (uc) of BaTiO3 (BTO) layer on (001) and (110) oriented substrates in order to elucidate the role of symmetry mismatch. Lattice mismatch for 3 uc of BTO and symmetry mismatch for 10 uc of BTO, both associated with local MnO6 octahedral distortions of the (001) LSMO within the first few uc, are revealed by scanning transmission electron microscopy. Interestingly, we find exchange bias along the in-plane [110]/[100] directions only for the (001) oriented samples. Polarized neutron reflectivity measurements confirm the existence of a layer with zero net moment only within (001) oriented samples. First principle density functional calculations show that even though the bulk ground state of LSMO is ferromagnetic, a large lattice constant together with an excess of La can stabilize an antiferromagnetic LaMnO3-type phase at the interface region and explain the experimentally observed exchange bias. Atomic scale tuning of MnO6 octahedra can thus be made possible via symmetry mismatch at heteroepitaxial interfaces. This aspect can act as a vital parameter for structure-driven control of physical properties.

| S-EPMC5587576 | biostudies-literature

The Glass-Transition Temperature of Supported PMMA Thin Films with Hydrogen Bond/Plasmonic Interface.

Project description:The interfacial effect is one of the significant factors in the glass-transition temperature (Tg) of the polymeric thin film system, competing against the free surface effect. Herein, the Tgs of poly (methyl methacrylate) (PMMA) films with different thicknesses and substrates are studied by fluorescence measurements, focusing on the influence of interfacial effects on the Tgs. The strong interaction between PMMA and quartz substrate leads to increased Tgs with the decreased thickness of the film. The plasmonic silver substrate causes enhanced fluorescence intensity near the interface, resulting in the delayed reduction of the Tgs with the increasing film thickness. Moreover, as a proof of the interface-dependent Tgs, hydrogen bonds of PMMA/quartz and molecules orientation of PMMA/silver are explored by the Raman spectroscopy, and the interfacial interaction energy is calculated by the molecular dynamics simulation. In this study, we probe the inter-relationship between the interfacial interactions arising from the different substrates and the Tg behavior of polymer thin films.

| S-EPMC6523344 | biostudies-literature

Giant Dielectric Permittivity in Ferroelectric Thin Films: Domain Wall Ping Pong.

Project description:The dielectric permittivity in ferroelectric thin films is generally orders of magnitude smaller than in their bulk. Here, we discover a way of increasing dielectric constants in ferroelectric thin films by ca. 500% by synchronizing the pulsed switching fields with the intrinsic switching time (nucleation of domain plus forward growth from cathode to anode). In a 170-nm lead zirconate titanate thin film with an average grain size of 850?nm this produces a dielectric constant of 8200 with the maximum nucleus density of 3.8??m(-2), which is one to three orders of magnitude higher than in other dielectric thin films. This permits smaller capacitors in memory devices and is a step forward in making ferroelectric domain-engineered nano-electronics.

| S-EPMC4594126 | biostudies-literature

Interface and surface stabilization of the polarization in ferroelectric thin films.

Project description:Ferroelectric perovskites present a switchable spontaneous polarization and are promising energy-efficient device components for digital information storage. Full control of the ferroelectric polarization in ultrathin films of ferroelectric perovskites needs to be achieved in order to apply this class of materials in modern devices. However, ferroelectricity itself is not well understood in this nanoscale form, where interface and surface effects become particularly relevant and where loss of net polarization is often observed. In this work, we show that the precise control of the structure of the top surface and bottom interface of the thin film is crucial toward this aim. We explore the properties of thin films of the prototypical ferroelectric lead titanate (PbTiO3) on a metallic strontium ruthenate (SrRuO3) buffer using a combination of computational (density functional theory) and experimental (optical second harmonic generation) methods. We find that the polarization direction and strength are influenced by chemical and electronic processes occurring at the epitaxial interface and at the surface. The polarization is particularly sensitive to adsorbates and to surface and interface defects. These results point to the possibility of controlling the polarization direction and magnitude by engineering specific interface and surface chemistries.

| S-EPMC7682414 | biostudies-literature

Kinetic control of tunable multi-state switching in ferroelectric thin films.

Project description:Deterministic creation of multiple ferroelectric states with intermediate values of polarization remains challenging due to the inherent bi-stability of ferroelectric switching. Here we show the ability to select any desired intermediate polarization value via control of the switching pathway in (111)-oriented PbZr0.2Ti0.8O3 films. Such switching phenomena are driven by kinetic control of the volume fraction of two geometrically different domain structures which are generated by two distinct switching pathways: one direct, bipolar-like switching and another multi-step switching process with the formation of a thermodynamically-stable intermediate twinning structure. Such control of switching pathways is enabled by the competition between elastic and electrostatic energies which favors different types of ferroelastic switching that can occur. Overall, our work demonstrates an alternative approach that transcends the inherent bi-stability of ferroelectrics to create non-volatile, deterministic, and repeatedly obtainable multi-state polarization without compromising other important properties, and holds promise for non-volatile multi-state functional applications.

| S-EPMC6427024 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data