Properties Of Ferroelectric Materials Research Articles

Impacts of low sintering temperature on microstructure, atomic bonds, and dielectric constant of barium titanate (BaTiO3) prepared by co-precipitation technique

Barium Titanate (BaTiO3 or BT) is one of which the most attractive ferroelectric materials that have been widely studied. The fabrication process affects the properties of ferroelectric materials where increasing the sintering temperature is one of the ways to improve their performance. In this study, BT has been synthesized using the co-precipitation technique. The samples were sintered for 4 h with varying sintering temperatures of 700°C and 800°C. The purpose of this study was to investigate the effects of variation of sintering temperatures on the microstructure, dielectric constant, and chemical bonds of BT. The micro structure observed by the X-Ray Diffraction (XRD) showed that the crystal size of the sample at 800°C was larger than the sample at 700°C. Furthermore, the Fourier Transform Infrared (FTIR) analysis revealed that increasing the sintering temperature decreased the intensity of the impurities’ peaks of C-H and C=O atomic bonds in the BT structure. The impurity that appear is the carbonate phase which does not decompose during the formation of BT. Moreover, based on the Resistance Capacitance Inductance (RCL Meter) examination, increasing the sintering temperatures could enhance the dielectric constant of the BT samples from 65 to 162. Thus, it can be inferred, that the increase in the sintering temperature could improve the crystal structure and decrease the impurities phases of the BT materials so that further could enhance the dielectric constant.

Evolution of the Interfacial Layer and Its Impact on Electric-Field-Cycling Behaviors in Ferroelectric Hf1-xZrxO2.

Doped HfO2 thin films, which exhibit robust ferroelectricity even with aggressive thickness scaling, could potentially enable ultralow-power logic and memory devices. The ferroelectric properties of such materials are strongly intertwined with the voltage-cycling-induced electrical and structural changes, leading to wake-up and fatigue effects. Such field-cycling-dependent behaviors are crucial to evaluate the reliability of HfO2-based functional devices; however, its genuine nature remains elusive. Herein, we demonstrate the coupling mechanism between the dynamic change of the interfacial layer and wake-up/fatigue phenomena in ferroelectric Hf1-xZrxO2 (HZO) thin films. Comprehensive atomic-resolution microscopy studies have revealed that the interfacial layer between the HZO and neighboring nonoxide electrode experienced a thickness/composition evolution during electrical cycling. Two theoretical models associated with the depolarization field are adopted, giving consistent results with the thickening of the interfacial layer during electrical cycling. Furthermore, we found that the electrical properties of the HZO devices can be manipulated by controlling the interface properties, e.g., through the choice of electrode match and hybrid cycling process. Our results unambiguously reveal the relationship between the interfacial layer and field-cycling behaviors in HZO, which would further permit the reliability improvement in HZO-based ferroelectric devices through interface engineering.

Electrical and Ferroelectric Properties of Undoped and Er-Doped PZT52/48 Electroceramics Synthesized by a Polymeric Precursor Method

The effect of Er on the structural and electrical properties of doped PZT 52/48 ceramics has been studied in this work. The ferroelectric properties (permittivity, ferro-paraelectric phase transition and hysteresis) of such materials are thus found to be strongly dependent on the degree of densification and structural phase development during sintering at high temperatures. In particular, the nature of the ferroelectric to paraelectric phase transition is in these materials that can be represented through the Curie-Weiss Law equation modified, appropriate for the characterization diffuse transitions. The substitution of Er3+ for (Zr,Ti)4+ is found to induce strong diffuse phase transition in these materials. The electrical properties reported in this work are in magnitude comparable to those exhibited by PZT52/48 materials.

Research progress of novel properties in several van der Waals ferroelectric materials

Ferroelectric (FE) materials possess electrically switchable spontaneous polarizations, showing broad applications in various functional devices. For the miniaturization of electronic devices, two-dimensional (2D) van der Waals (vdW) ferroelectric materials and the corresponding bulk counterparts have aroused more interest of researchers. Recently, several kinds of 2D vdW ferroelectrics have been fabricated in experiment. These 2D vdW FEs, as well as their bulk counterparts, exhibit novel properties as demonstrated in experiment or predicted in theory. This paper is to review the recent progress of novel properties of several vdW ferroelectrics. In Section II, we introduce the unusual ferroelectric property—a uniaxial quadruple potential well for Cu displacements—enabled by the van der Waals gap in copper indium thiophosphate (CuInP<sub>2</sub>S<sub>6</sub>). The electric field drives the Cu atoms to unidirectionally cross the vdW gaps, which is distinctively different from dipole reorientation, resulting in an unusual phenomenon that the polarization of CuInP<sub>2</sub>S<sub>6</sub> aligns against the direction of the applied electric field. The potential energy landscape for Cu displacements is strongly influenced by strain, accounting for the origin of the negative piezoelectric coefficient and making CuInP<sub>2</sub>S<sub>6</sub> a rare example of a uniaxial multi-well ferroelectric. In Section III, we introduce the distinct geometric evolution mechanism of the newly reported M<sub>2</sub>Ge<sub>2</sub>Y<sub>6</sub> (M = metal, X = Si, Ge, Sn, Y = S, Sn, Te) monolayers and a high throughput screening of 2D ferroelectric candidates based on this mechanism. The ferroelectricity of M<sub>2</sub>Ge<sub>2</sub>Y<sub>6</sub> originates from the vertical displacement of Ge-dimer in the same direction driven by a soft phonon mode of the centrosymmetric configuration. Another centrosymmetric configuration is also dynamically stable but higher in energy than the ferroelectric phase. The metastable centrosymmetric phase of M<sub>2</sub>Ge<sub>2</sub>Y<sub>6</sub> monolayers allows a new two-step ferroelectric switching path and may induce novel domain behaviors. In Section IV, a new concept about constructing 2D ferroelectric QL-M<sub>2</sub>O<sub>3</sub>/graphene heterostructure to realize monolayer-based FE tunnel junctions or potentially graphene p-n junctions is reviewed. These findings provide new perspectives of the integration of graphene with monolayer FEs, as well as related functional devices. Finally, the challenge and prospect of vdW ferroelectrics are discussed, providing some perspective for the field of ferroelectrics.

Construction and Research of Amorphous Alloys and Ferroelectric Materials in the Digital Logistics Platform

People have higher and higher requirements for the size, sensitivity, measurement range, repeatability error, and power consumption cost of sensors and memories in the field of electronic information technology. “Logistics” as another new industry in the modern social division of labor is showing its infinite vitality, and the rise of digital logistics is the use of network technology to meet the development of this era. Based on the application of amorphous alloys and ferroelectric materials to the construction of logistics digital platform, this paper is aimed at demonstrating the function of nonstatic alloys and ferroelectric materials to promote the data storage of logistics digital platform and other aspects from multiple perspectives. This article is mainly divided into two general directions. The first is to study the physical and chemical properties of amorphous alloys and ferroelectric materials separately. The content of the article is more complete by referring to relevant research literature or obtaining relevant targeted information; the basic structure of the digital logistics platform is modeled, and the application of amorphous alloys and ferroelectric materials is mainly applied to the two parts of the data service composition and the data layer. This arrangement is based on the sensor as the key to data processing. Location is of great significance to the entire platform system. The experimental results show that the digital logistics platform constructed in this paper can reach a score of 7.75 in terms of data security and 7.39 in terms of flexibility. It also increases the efficiency of the entire operation process.

Retracted] Realization of a Noncontact IC Chip with Embedded Ferroelectric Memory in an Auxiliary Timing Device for Sports Games

The research direction of the new generation of embedded memory can be summarized into two types of embedded nonvolatile memory and embedded volatile memory; the research on online testing of embedded memory started in the past ten years, and there are few research results. This article analyzes the feasibility of the noncontact IC chip in the embedded ferroelectric memory of the sports game auxiliary timing device and is aimed at obtaining an optimized embedded ferroelectric memory by analyzing the relevant data to achieve the update and update of the sports game timing device system. Early sports event timing methods generally use manual timing (stopwatch) or camera shooting timing; this method is inefficient, poor real‐time, huge workload, and prone to errors. This research mainly focuses on the analysis and discussion of the material structure and performance of the embedded ferroelectric memory and the process of noncontact IC chip. This article uses custom welding circuit technology to prepare the best ferroelectric filter in the test part and verifies the influence of temperature on the material; in order to understand the properties of ferroelectric materials at the electronic and atomic level, a first‐order statistical method is obtained. The numerical calculation results of the experiment verify that the evaluation value of the serial port synchronization module as a whole exceeds the pulse synchronization; the network synchronization as a whole exceeds the code synchronization, and the result of the network time service module is the opposite, but as a whole, each module of the noncontact IC chip has strong performance adaptability; in the application of auxiliary timing, the maintainability of noncontact IC chip is quite outstanding, and the maximum value is 7.97; a large number of complex simulation system tasks can be completed by simple and direct tasks.

Exploring Causal Physical Mechanisms via Non-Gaussian Linear Models and Deep Kernel Learning: Applications for Ferroelectric Domain Structures.

Rapid emergence of multimodal imaging in scanning probe, electron, and optical microscopies has brought forth the challenge of understanding the information contained in these complex data sets, targeting the intrinsic correlations between different channels, and further exploring the underpinning causal physical mechanisms. Here, we develop such an analysis framework for Piezoresponse Force Microscopy. We argue that under certain conditions, we can bootstrap experimental observations with the prior knowledge of materials structure to get information on certain nonobserved properties, and demonstrate linear causal analysis for PFM observables. We further demonstrate that the strength of individual causal links between complex descriptors can be ascertained using the deep kernel learning (DKL) model. In this DKL analysis, we use the prior information on domain structure within the image to predict the physical properties. This analysis demonstrates the correlative relationships between morphology, piezoresponse, elastic property, etc., at nanoscale. The prediction of morphology and other physical parameters illustrates a mutual interaction between surface condition and physical properties in ferroelectric materials. This analysis is universal and can be extended to explore the correlative relationships of other multichannel data sets, and allow for high-fidelity reconstruction of underpinning functionalities and physical mechanisms.

DFT based studies on the structural, electronic and optical properties of LiNbO3 using some hybrid techniques

Structural, electronic, and optical properties of ferroelectric material, Lithium niobate (LiNbO3) are explored and studied using two different techniques namely, OLCAO-MGGA-TB09+c and OLCAO-GGA-PBES + U under the framework of density functional theory (DFT). The electronic properties such as band diagram, the effective mass of charge carriers, the total density of state (TDOS), and partial density of state (PDOS) are investigated in depth. Band gap values obtained using MGGA-TB09+c is 3.79 eV whereas, it is 3.78 eV for GGA-PBES + U. Furthermore, several optical properties such as dielectric constant, reflectivity, refractive index, optical conductivity, loss function, and absorption coefficient have also been extracted. It is seen that the results so obtained are consistent with experimental data which shows the soundness of our calculations. From the statistical analysis, it is found that both the techniques provide very good results on electronic and optical properties of LiNbO3 compared to existing computational work as both give an approximation of experimental data. The methods presented here will be useful for researchers to get accurate results on structural, electronic, and optical properties of other materials.

Ferroelectric Materials for Solar Energy Scavenging and Photodetectors

AbstractThe photovoltaic devices based on ferroelectrics have drawn plenty of attention for providing a promising solar energy harvesting technology and efficient photodetectors. In this review, mainly the photoelectric properties of ferroelectric materials are introduced. First, three different types of ferroelectrics and primary representative materials are reviewed. Second, four existing principles and mechanisms of the photovoltaic effect in ferroelectrics are studied in great detail. Then, the typical design construction utilizing ferroelectrics for solar energy scavenging, photodetectors, and other photovoltaic device architectures is summarized. Lastly, the properties and characteristics of photovoltaic devices based on ferroelectrics are reviewed in the form of tables and the prospect of ferroelectric photovoltaic devices is discussed.

The Rise of Ferroelectricity at Nanoscale: Nanoelectronics is rediscovering the ferroelectricity

We present a comprehensive review of the emerging nanoscale ferroelectric materials used in novel nanoelectronics devices. First, we outline specific physical and electronic properties of ferroelectric materials, then we focus on two main classes of ferroelectrics based on hafnium oxide (HfO₂) and 2D materials. The former exhibits unique characteristics, making it the target of subsequent discussions. Their remanent polarization, coercive field, permittivity, nanometric scale thickness (up to 10 nm), and CMOS compatibility distinguish HfO₂ compounds from any other existing ferroelectrics. The ever increasing need to integrate nanotechnology with electronics has given rise to the realization of newer conceptual devices and components based on ferroelectric HfO₂, such as phase shifters, phased antenna arrays (PAAs), filters, field-effect transistors (FETs,) ferroelectric tunneling junctions (FTJs), memristors/memtransistors (neuromorphic nanoelectronics), and negative capacitance ferroelectric transistors. For each of these applications, we present state-of-the-art solutions that were designed, fabricated, and tested. At the same time, the main drawbacks (especially those related to materials and technological issues) are discussed. This article provides an in-depth overview of present and future challenges in the domain of ferroelectric-based nanoelectronics, with the hope that it will trigger the curiosity of researchers interested in the further advancement of this emerging field of science.

Effect of chromium substitution on the dielectric, ferroelectric and piezoelectric properties of PLNZNT ceramics (P=Pb2+, L=La3+, N=Nd3+, Z=Zr4+, N=Nb5+, T=Ti4+)

Piezoelectricity is one of the renewable and clean electrical energy sources, as it is generated from materials specially manufactured for this purpose in proportions and scales called piezoelectric materials, that is, electricity resulting from mechanical work that produces the electric field, and this is known as the direct piezoelectric effect. An inverse mechanical effect can also be observed when an electric field is applied to the same piezoelectric material that deforms and returns to its original shape after the electric field is removed. In order to contribute to improving the properties of these materials that have been prepared from insulating ceramic materials having an equivalent formula: Pb0.975 La0.015 Nd0.01 [(Zr 0,524 Ti 0,476) 0.9875 -3/4 z Nb0.005 Crz]O3 abbreviated PLNZCNT (z = 0%, 0.5%, 0.75%, 1%, 1.25%, 1,5% and 2%). The formation of pure single-phase perovskite compounds of tetragonal symmetry for all samples was confirmed by X-ray diffraction (XRD) analyzes. The scanning electron micrographs show that the grains have melted, most of the separating walls have disappeared, and the average grain size has increased. Information about the effects of chromium concentration on the measured properties was obtained based on temperature and frequency measurements of the dielectric properties of PLNZNT ceramics, represented by an increase in Curie temperature with increasing Cr3+ concentration. The ferroelectric properties of materials are characterized by the presence of a polarization hysteresis cycle as a function of the applied electric field (P-E). To measure the piezoelectric and electromechanical properties at room temperature, was used by the standard resonance and anti-resonance method. It was found that the sample E2 (0.75%) sintered at 1200°C achieves excellent dielectric, ferroelectric and piezoelectric properties (𝜺r=24394.51, tan δ =0.072 and Tc = 378K). The values of saturated electric polarization (Ps=29.61 µC/cm²), remnant electric polarization (Pr=24.63 µC/cm²) and coercive electric field (Ec=0.905kV/mm), as well as piezoelectric charge coefficient (d33 = 435 pC/N) for sample E2 (0.75%).

Structural analysis, ferroelectric and dielectric properties of single-component organic multifunctional materials

Structural analysis, ferroelectric and dielectric properties of single-component organic multifunctional materials

Prospective features of multiferroic tungsten bronze ceramics and its futuristic applications

The changing day-to-day requirements and enhance trend in innovative technology demands materials with assortment of applications. Ferroelectric ceramics are one of the materials which are highly serving the technological requirements for a long time. The structure of tungsten bronze ferroelectric ceramics has attracted the awareness of material scientists to make effort to shape them for a particular application. The metal ions are generally distributed at tetrahedral (A) and octahedral (B)-sites in ferroelectric ceramics which are finally responsible for the electrical and magnetic properties. Since, for every material scientist it’s always a challenge to make it possible to place a particular metal ion on a particular site for a desired application, therefore, knowledge of substitution of different metal cations plays a critical role to synthesize these materials for the required scientific & industrial based applications. In the present chapter we are exploring that how various transition metal substitution at B site or A site help us to understand the structure deeply but also help to control the properties of ferroelectric materials.

Integrated Tapping Mode Kelvin Probe Force Microscopy with Photoinduced Force Microscopy for Correlative Chemical and Surface Potential Mapping.

Kelvin probe force microscopy (KPFM) is a popular technique for mapping the surface potential at the nanoscale through measurement of the Coulombic force between an atomic force microscopy (AFM) tip and sample. The lateral resolution of conventional KPFM variants is limited to between ≈35 and 100nm in ambient conditions due to the long-range nature of the Coulombic force. In this article, a novel way of generating the Coulombic force in tapping mode KPFM without the need for an external AC driving voltage is presented. A field-effect transistor (FET) is used to directly switch the electrical connectivity of the tip and sample on and off periodically. The resulting Coulomb force induced by Fermi level alignment of the tip and sample results in a detectable change of the cantilever oscillation at the FET-switching frequency. The resulting FET-switched KPFM delivers a spatial resolution of ≈25nm and inherits the high operational speed of the AFM tapping mode. Moreover, the FET-switched KPFM is integrated with photoinduced force microscopy (PiFM), enabling simultaneous acquisitions of high spatial resolution chemical distributions and surface potential maps. The integrated FET-switched KPFM with PiFM is expected to facilitate characterizations of nanoscale electrical properties of photoactive materials, semiconductors, and ferroelectric materials.

A T-shaped gate tunneling field effect transistor with negative capacitance, super-steep subthreshold swing

With the development of semiconductor technology, the size of traditional metal oxide semiconductor field effect transistor devices continues to decrease, but it cannot meet the requirements of high performance and low power consumption. Low power tunneling field effect transistor (TFET) has gradually become the focus of researchers. This paper proposes a novel T-shaped gate TFET based on the silicon with the negative capacitance (NC-TGTFET). On the basis of TGTFET, ferroelectric material (HZO) is used as gate dielectric. The simulation results show that, compared with the traditional TGTFET, the opening order and sensitivity of the two tunneling junctions are different. The influences of thickness and the doping concentration of pocket and ferroelectric material properties on the characteristics of NC-TGTFET is also discussed by Sentaurus simulation tool. Furthermore, the negative capacitance of ferroelectric material makes NC-TGTFET have a very steep subthreshold swing (18.32 mV/dec) at the range of drain current from 1 × 10−15 to 1 × 10−7 A μm−1. And the on-state current (V g = 0.5 V, V d = 0.5 V) is 1.52 × 10−6 A μm−1.

Experimental Characterization of Ferroelectric Capacitor Circuits for the Realization of Simply Designed Electroceuticals

Currently, a large number of neurostimulators are commercially available for the treatment of drug-resistant diseases and as an alternative to pharmaceuticals. According to the current state of the art, such highly engineered electroceuticals require bulky battery units and necessitate the use of leads and extensions to connect the implantable electronic device to the stimulation electrodes. The battery life and the use of wired electrodes constrain the long-term use of such implantable systems. Furthermore, for therapeutic success and patient safety, it is of utmost importance to keep the stimulation current within a safe range. In this paper, we propose an implantable system design that consists of a low number of passive electronic components and does not require a battery. The stimulation parameters and power are transmitted inductively using an extracorporeal wearable transmitter at frequencies below 1 MHz. A simple circuit design approach is presented to achieve a closed-loop control of the stimulation current by exploiting the nonlinear properties of ferroelectric materials in ceramic capacitors. Twenty circuit topologies of series- and/or parallel-connected ceramic capacitors are investigated by measurement and are modeled in Mathcad. An approximately linear increase in the stimulation current, a stabilization of the stimulation current and an unstable state of the system were observed. In contrast to previous results, specific plateau ranges of the stimulation current can be set by the investigated circuit topologies. For further investigations, the consistency of the proposed model needs to be improved for higher induced voltage ranges.

Optical properties of a new (1−x)Bi1/2Na1/2TiO3 + xPr1/2Na1/2TiO3 solid solution system

The solid solutions of Bi1/2Na1/2TiO3 and Pr1/2Na1/2TiO3 materials were successfully synthesized by a simple chemical method. X-ray diffraction measurements of the Pr1/2Na1/2TiO3-modified Bi1/2Na1/2TiO3 materials indicated that Pr1/2Na1/2TiO3 was well dissolved into the host Bi1/2Na1/2TiO3 materials, resulting in the random incorporation of Pr cations in the host materials. The optical bandgap of the Pr1/2Na1/2TiO3-modified Bi1/2Na1/2TiO3 materials slightly reduced as increasing Pr1/2Na1/2TiO3 concentrations, from 3.04 eV for the pure Bi1/2Na1/2TiO3 material to 2.95 eV for the sample with 9 mol.% of Pr1/2Na1/2TiO3. We observed strong photoluminescence emission at 610 nm in the Pr1/2Na1/2TiO3-modified Bi1/2Na1/2TiO3 system, which originated from electron transitions from 3P0 to 3H6 levels of Pr3+ cations. We expected that our work would provide a simple method to combine photoluminescence properties in lead-free ferroelectric materials for smart electronic device applications.

Tunable optical properties of Bi1/2Na1/2TiO3 materials via Sm1/2Na1/2TiO3 addition

In this work, the Sm1/2Na1/2TiO3-addition Bi1/2Na1/2TiO3 materials as solid solutions were synthesized via a chemical route method. The X-ray diffraction and Raman scattering results indicated that Sm1/2Na1/2TiO3 materials were well solute into the host Bi1/2Na1/2TiO3 materials to form solid solutions. The optical bandgap of the pure Bi1/2Na1/2TiO3 materials was estimated from ultraviolet–visible spectroscopy of 3.07 eV. The bandgap slightly reduced to 2.94 eV as increasing the Sm1/2Na1/2TiO3 amounts up to 9 mol.%. Strong photoluminescence (PL) of Sm1/2Na1/2TiO3-addition Bi1/2Na1/2TiO3 materials was obtained in the visible wavelength range of 550–750 nm which related to photoluminescence of Sm cations randomly incorporated into the host lattice of Bi1/2Na1/2TiO3 materials. Our work was promised to show a new method to integrate the PL properties in lead-free ferroelectric materials.

Ferroelectric-relaxor boundary in La-modified Pb(Mg1/3Nb2/3)O3-xPbTiO3 crossover showing enhanced dielectric and piezoelectric properties

The dielectric and piezoelectric properties of La-modified Pb(Mg1/3Nb2/3)O3-xPbTiO3 crossover ceramics were systematically studied. In this crossover region, there is a ferroelectric-relaxor boundary separating the ferroelectric and relaxor states, which is determined by the spontaneous transition from relaxor to ferroelectric state with decreasing temperature. At the ferroelectric-relaxor boundary, the maximum permittivity increases from 18,200 to 23,500, and piezoelectric coefficient (d33) increases from 300 pC/N to 450 pC/N accompanied by the electrostrain improved from 0.09% to 0.12%, as compared with adjacent ferroelectric specimen. These enhancements may originate from the low energy barrier for polarization rotation induced by the existence of spontaneous transition and the coexistence of macrodomain and polar nanodomain configuration. This work indicates that the ferroelectric-relaxor boundary in crossover region may become an effective approach to enhance the dielectric and piezoelectric properties of ferroelectric materials.

Estimation of Ferroelectric Material Properties and Phase-Shifter Design Key Parameters Influence on Its Figure of Merit for Optimization of Development Process

A model of the estimation of the ferroelectric-based phase-shifter figure of merit concerning the material properties and phase-shifter design parameters is presented. The influence of ferroelectric material tunability and losses on phase-shifter characteristics are analyzed. Two approaches to phase-shifter design (transmission line and band-pass filter) are considered. The review of the published results on the ferroelectric phase-shifter design was performed to approve the method proposed. Recommendations to optimize the phase-shifter development process are suggested on the basis of the elaborated model and analysis performed.