Electrical Characteristics Research Articles

The Effect of the TiO2 Anodization Layer in Pedicle Screw Conductivity: An Analytical, Numerical, and Experimental Approach.

The electrical stimulation of pedicle screws is a technique used to ensure its correct placement within the vertebrae pedicle. Several authors have studied these screws' electrical properties with the objective of understanding if they are a potential source of false negatives. As titanium screws are anodized with different thicknesses of a high electrical resistance oxide (TiO2), this study investigated, using analytical, numerical, and experimental methods, how its thickness may affect pedicle screw's resistance and conductivity. Analytical results have demonstrated that the thickness of the TiO2 layer does result in a significant radial resistance increase (44.21 mΩ/nm, for Ø 4.5 mm), and a decrease of conductivity with layers thicker than 150 nm. The numerical approach denotes that the geometry of the screw further results in a decrease in the pedicle screw conductivity, especially after 125 nm. Additionally, the experimental results demonstrate that there is indeed an effective decrease in conductivity with an increase in the TiO2 layer thickness, which is also reflected in the screw's total resistance. While the magnitude of the resistance associated with each TiO2 layer thickness may not be enough to compromise the ability to use anodized pedicle screws with a high-voltage electrical stimulator, pedicle screws should be the subject of more frequent electrical characterisation studies.

Crystal Structure and Spectroscopic Characterization of a New Hybrid Compound, (C12H17N2)2[CdBr4], for Energy Storage Applications.

Organic-inorganic hybrid materials have recently found a vast variety of applications in the fields of energy storage and microelectronics due to their outstanding electric and dielectric characteristics, including high dielectric constant, low conductivity, and low dielectric loss. However, despite the promising properties of these materials, there remains a need to explore novel compounds with improved performance for practical applications. In this research paper, the focus is on addressing this scientific challenge by synthesizing and characterizing the new-centrosymmetric (C12H17N2)2[CdBr4] crystal. This compound offers potential advancements in energy storage technologies and microelectronics due to its unique structural and electronic properties. The chemical mentioned above crystallizes in the monoclinic system, and its protonated amine (C12H17N2)+ and isolated anion [CdBr4]2- are bound by C-H···π and N-H···Br hydrogen bonds to form its zero-dimensional structure. Through optical absorption analysis, the semiconductor nature of the material is verified, showcasing a band gap of around 2.9 eV. Furthermore, an in-depth examination of Nyquist plots reveals the material's electrical characteristics' sensitivity to frequency and temperature variations. By applying Jonscher's power law to analyze ac conductivity plots, it is observed that the variation in the exponent "s" accurately characterizes the conduction mechanism, aligning with CBH models. The compound exhibits low dielectric loss values and a high permittivity value (ε ∼ 105), making it a promising candidate for energy storage applications. By managing the scientific challenge of improving material performance for energy storage and microelectronics, this research contributes to advancing the field and opens avenues for further exploration and application of organic-inorganic hybrid materials.

Spintronic device in SWCNT-FET configuration based on chromium oxides thin films consisting of half-metallic ferromagnetic CrO2

Spintronic device architectures consisting of ferromagnetic chromium oxide electrodes in single-walled carbon nanotubes field effect transistor (SWCNT-FET) configuration have been fabricated to act as strategic building blocks for next generation super-compact high-speed nanoelectronic devices for logic and memory operations. Stable thin films of chromium oxides consisting of half-metallic ferromagnetic chromium-di-oxide (CrO2) were pulsed laser deposited (PLD) over lattice-matched rutile-type-tetragonal intermediate TiO2 thin layers over thermally oxidized Si substrates for engineering of the spintronic device structure. Focused ion beam (FIB) milling was applied to the ferromagnetic chromium oxide thin films for patterning of the source (S) and (D) electrodes. Typical electrical characteristics derived by lnρ vs. T−1/2 plots confirmed spin-dependent transport (SDT) as the dominant mechanism of electrical conduction upto temperatures of ∼280 K along with negative magnetoresistance (MR) of ∼30 % at 278 K. Electrical characteristics (output and transfer) of the spintronic device structure were drawn under application of magnetic field (H) in out-of-plane geometry at the temperatures of 5.6 K, 250 K & 300 K. Drain current (Id) is demonstrated to be controlled effectively as a function of gate bias (Vg) for different fixed Vd-biases at all the device operating temperatures. Change in %MR as a function of gate voltage (Vg) was acquired at T = 250 &T = 300 K that displayed higher %MR change under out-of-plane geometry of applied field of 0.75 T of the spintronic device operation.

Porous Crystalline Materials Based on Tetrathiafulvalene and Its Analogues: Assembly, Charge Transfer, and Applications.

ConspectusThe directed synthesis and functionalization of porous crystalline materials pose significant challenges for chemists. The synergistic integration of different functionalities within an ordered molecular material holds great significance for expanding its applications as functional materials. The presence of coordination bonds connected by inorganic and organic components in molecular materials can not only increase the structural diversity of materials but also modulate the electronic structure and band gap, which further regulates the physical and chemical properties of molecular materials. In fact, porous crystalline materials with coordination bonds, which inherit the merits of both organic and inorganic materials, already showcase their superior advantages in optical, electrical, and magnetic applications. In addition to the inorganic components that provide structural rigidity, organic ligands of various types serve as crucial connectors in the construction of functional porous crystalline materials. In addition, redox activity can endow organic linkers with electrochemical activity, thereby making them a perfect platform for the study of charge transfer with atom-resolved single-crystal structures, and they can additionally serve as stimuli-responsive sites in sensor devices and smart materials.In this Account, we introduce the synthesis, structural characteristics, and applications of porous crystalline materials based on the famous redox-active units, tetrathiafulvalene (TTF) and its analogues, by primarily focusing on metal-organic frameworks (MOFs) and covalent organic frameworks (COFs). TTF, a sulfur-rich conjugated molecule with two reversible and easily accessible oxidation states (i.e., radical TTF•+ cation and TTF2+ dication), and its analogues boast special electrical characteristics that enable them to display switchable redox activity and stimuli-responsive properties. These inherent properties contribute to the enhancement of the optical, electrical, and magnetic characteristics of the resultant porous crystalline materials. Moreover, delving into the charge transfer phenomena, which is key for the electrochemical process within these materials, uncovers a myriad of potential functional applications. The Account is organized into five main sections that correspond to the different properties and applications of these materials: optical, electrical, and magnetic functionalities; energy storage and conversion; and catalysis. Each section provides detailed discussions of synthetic methods, structural characteristics, the physical and chemical properties, and the functional performances of highlighted examples. The Account also discusses future directions by emphasizing the exploration of novel organic units, the transformation between radical cation TTF•+ and dication TTF2+, and the integration of multifunctionalities within these frameworks to foster the development of smart materials for enhanced performance across diverse applications. Through this Account, we aim to highlight the massive potential of TTF and its analogues-based porous crystals in chemistry and material science.

Effects of Fe Contamination on the Reliability of Gate Oxide Integrity in Advanced CMOS Technology

Fe contamination has always been one of the most critical issues in the integrated circuit (IC) industry due to its catastrophic effect on device reliability and electrical characteristics. With complementary metal oxide semiconductor (CMOS) technology scaling down, this issue has been attracting more attention. In this paper, the impact of Fe impurity on the reliability of gate oxide integrity (GOI) in advanced CMOS technology is investigated. Intentional contamination of polysilicon gates was conducted in both boron- and phosphorus-doped devices. Failure analysis of the gate oxide was conducted with high-resolution transmission electron microscopy (HRTEM) and the energy dispersive X-ray (EDX) technique. The experimental results disclose that the properties of PMOS are much more sensitive to Fe contamination than those of NMOS. It is suggested that the reason for the above phenomena is that Fe precipitates at the PMOS gate/oxide interface but dissolves uniformly in the NMOS poly gate due to lower formation energy of the FeB pair (0.65 eV) in PMOS than that of the P4-Fe cluster (3.2 eV) in NMOS.

Investigation into negative corona discharge in steam jets and distribution characteristics of charged steam jets

Electricity provides a wide range of benefits for plant growth, and the electric field created by a charged steam jet exhibits significant potential for application in this field. This study investigates the electrical characteristics of charged steam jets, including the corona-discharge process, distribution of electric fields, and deposition currents. By installing a needle-ring electrode near the steam-jet exit, high-potential charged steam is generated within a confined space through the corona charging of droplets in the steam. The humid environment inside the steam jet considerably reduces the corona current compared with that of air. The outlet current is identified as a critical factor for assessing the charged steam-jet behaviour, with a higher outlet current indicating a stronger electric field and deposition current. The configuration of the electrode and the steam operational conditions, particularly the latter, affect the outlet current. Experimental results highlight the different electrical distribution characteristics of wet and saturated steam jets. Notably, the distributions of electric field and deposition currents, along with the depositional droplets and absolute-humidity increments exhibit asymmetry above and below the steam jet. This paper presents a discussion on the formation, development, and dissipative processes of charged droplets and an analysis into their possible movement trajectories under various forces. Generally, the asymmetric distribution of charged steam jets is caused by the asymmetric distribution of charged droplets or water-cluster molecules, which becomes more pronounced as one departs further from the steam-jet exit.

Polarization-dependent electrical transport and thermoelectric properties in (010) surface of λ-Ti3O5

In recent research, the (010) surface of λ-Ti3O5 has demonstrated outstanding capabilities in light absorption and molecular adsorption, promising various applications. In this study, we employed density functional theory (DFT) to analyze the optical and thermoelectric properties of the (010) surface of λ-Ti3O5. Our findings reveal the excellent in-plane anisotropy of the optical anisotropy of bulk λ-Ti3O5 and thermoelectric properties in its (010) surface. The figure of merit (ZT) along the groove structure direction reaches 2.4, while the ZT perpendicular to it is only 0.85. In addition, the electrical transport characteristics along the (010) surface exhibit significant nonlinear characteristics. Our research results indicate that it has the potential to become a favorable material for optical and electronic devices.

Donor-induced electrically charged defect levels: examining the role of indium and n-type defect-complexes in germanium

Defect levels induced by defect-complexes in Ge play important roles in device fabrication, characterization, and processing. However, only a few defect levels induced by defect-complexes have been studied, hence limiting the knowledge of how to control the activities of numerous unknown defect-complexes in Ge. In this study, hybrid density functional theory calculations of defect-complexes involving oversize atom (indium) and n-type impurity atoms in Ge were performed. The formation energies, defect-complex stability, and electrical characteristics of induced defect levels in Ge were predicted. Under equilibrium conditions, the formation energy of the defect-complexes was predicted to be within the range of 5.90–11.38 eV. The defect-complexes formed by P and In atoms are the most stable defects with binding energy in the range of 3.31-3.33 eV. Defect levels acting as donors were induced in the band gap of the host Ge. Additionally, while shallow defect levels close to the conduction band were strongly induced by the interactions of Sb, P, and As interstitials with dopant (In), the double donors resulting from the interactions between P, As, N, and the host atoms including In atom are deep, leading to recombination centers. The results of this study could be applicable in device characterization, where the interaction of In atom and n-type impurities in Ge is essential. This report is important as it provides a theoretical understanding of the formation and control of donor-related defect-complexes in Ge.

Band-Gap Narrowing and Electric Transport Regulation of Hybrid Perovskites via Pressure Engineering.

Lead-free organic-inorganic hybrid perovskites are one class of promising optoelectronic materials that have attracted much attention due to their outstanding stability and environmentally friendly nature. However, the intrinsic band gap far from the Shockley-Queisser limit and the inferior electrical properties largely limit their applicability. Here, a considerable band-gap narrowing from 2.43 to 1.64 eV with the compression rate up to 32.5% is achieved via high-pressure engineering in the lead-free hybrid perovskite MA3Sb2I9. Meanwhile, the electric transport process changes from the initial interaction of both ions and electrons to only the contribution of electrons upon compression. The alteration in electrical characteristics is ascribed to the vibration limitation of organic ions and the enhanced orbital overlap, resulting from the reduction of the Sb-I bond length through pressure-induced phase transitions. This work not only systematically investigates the correlation between the structural and optoelectronic properties of MA3Sb2I9 but also provides a potential pathway for optimizing electrical properties in lead-free hybrid perovskites.

Data-driven estimation of battery state-of-health with formation features

Accurately estimating the state-of-health (SOH) of a battery is crucial for ensuring battery safe and efficient operation. The lifetime of lithium-ion batteries (LIBs) starts from their manufacture, and the performance of LIBs in the service period is highly related to the formation conditions in the factory. Here, we develop a deep transfer ensemble learning framework with two constructive layers to estimate battery SOH. The primary approach involves a combination of base models, a convolutional neural network to combine electrical features with spatial relationships of thermal and mechanical features from formation to subsequent cycles, and long short-term memory to extract temporal dependencies during cycling. Gaussian process regression (GPR) then handles SOH prediction based on this integrated model. The validation results demonstrate highly accurate capacity estimation, with a lowest root-mean-square error (RMSE) of 1.662% and a mean RMSE of 2.512%. Characterization on retired cells reveals the correlation between embedded formation features and their impact on the structural, morphological, and valence states evolution of electrode material, enabling reliable prediction with the corresponding interplay mechanism. Our work highlights the value of deep learning with comprehensive analysis through the relevant features, and provides guidance for optimizing battery management.

Performance Evaluation of Physical Properties on Zinc Sulfide (ZnS)-based Field Effect Transistor

The paper presents the performance evaluation of physical properties on Zinc Sulfide (ZnS)-based Field Effect Transistor. The most famous III-V compound-based semiconductor devices have several affected to the environment and the toxic contents are directly responded to the society. Due to the lack of technology on nontoxic compound-based semiconductor device fabrications, the novel device with II-VI compound materials are challenging issues for the environments. The specific objectives of doing research on fabrication of II-VI compound-based semiconductor devices in advanced laboratories are to emphasize the numerical modeling of the device structure and designing the FET based on ZnS material, to contribute the mathematical model for physical characteristics of the FET structure and the modification of the device structure will be easily established by using numerical simulation. The mathematical analyses on physical properties of device structure with ZnS material are confirmed and observed the several properties of electrical and electronic characteristics. The detailed implementations for ZnS-based FET devices are performed and evaluated the performance of the developed FET devices. There are two steps analyses in physical properties of ZnS-based FET devices with numerical implementation by MATLAB languages. The results observed in this study could be confirmed with the recent works from several research laboratories and the developed ZnS-based FET devices could be utilized in high performance wide band applications on switching in the power electronics and amplification purposes in modern amplifier design in real world applications.

Carbon nanomaterials: Pioneering innovations in bioimaging and biosensing technologies

Carbon-based nanomaterials, including carbon nanotubes, graphene, carbon dots, carbon nano onions, and carbon nano horns, exhibit exceptional properties such as high electrical and thermal conductivity, mechanical strength, and biocompatibility. These characteristics make them attractive for various biomedical applications, particularly in bioimaging and biosensing. In bioimaging, carbon-based nanomaterials offer several advantages. Their unique properties enable precise imaging of biological events in cells, tissues, and organs, with minimal interference in living processes. By leveraging these properties, researchers can achieve high-resolution imaging for accurate diagnosis and therapy. Similarly, carbon-based nanomaterials are crucial in biosensing applications. They provide a platform for developing highly sensitive biosensors due to their distinctive electrical properties and surface characteristics. Functionalizing these nanomaterials with specific biomolecules or receptors allows for the detection and extraction of target molecules with exceptional precision and sensitivity, inspired by principles found in living systems. A review article focusing on the applications of carbon-based nanomaterials in bioimaging and biosensing would provide insights into their potential in advancing biotechnology. This article discusses a variety of carbon-based nanomaterials, including carbon nanotubes, graphene, carbon dots, carbon nano onions, and carbon nano horns, emphasizing their unique properties and applications in bioimaging and sensing. The review emphasizes the importance of detection accuracy and sensitivity in biomedical applications and investigates how carbon-based nanomaterials help to advance biotechnology. This exploration will allow researchers to explore and create novel diagnostic and therapeutic methods.

Versatile Papertronics: Photo-Induced Synapse and Security Applications on Papers.

Paper is a readily available material in nature. Its recyclability, eco-friendliness, portability, flexibility, and affordability make it a favored substrate for researchers seeking cost-effective solutions. Electronic devices based on solution process are fabricated on paper and banknotes using PVK and SnO2 nanoparticles. The devices manufactured on paper substrates exhibit photosynaptic behavior under ultraviolet pulse illumination, stemming from numerous interactions on the surface of the SnO2 nanoparticles. A light-modulated artificial synapse device is realized on a paper at a low voltage bias of -0.01V, with an average recognition rate of 91.7% based on the Yale Face Database. As a security device on a banknote, 400 devices in a 20 × 20 array configuration exhibited random electrical characteristics owing to the local morphology of the SnO2 nanoparticles and differences in the depletion layer width at the SnO2/PVK interface. The security Physically Unclonable Functions (PUF) key based on the current distribution extracted at -1V show unpredictable reproducibility with 50% uniformity, 48.7% inter-Hamming distance, and 50.1% bit-aliasing rates. Moreover, the device maintained its properties for more than 210 days under a curvature radius of 8.75mm and bias and UV irradiation stress conditions.

Transient synergistic damage mechanism and characterization of silicon bipolar junction transistor

The silicon bipolar junction transistor (Si BJT) is widely used as a discrete device, but it is susceptible to damage from both ionization and displacement in nuclear radiation environments. Current research primarily focuses on steady-state irradiation to study the synergistic damage mechanism caused by ionization and displacement, with a lack of research on transient synergistic damage. This paper studies the energy deposition and distribution with different incident angles and energies when neutrons and photons are simultaneously incident, and found similarities in the energy deposition between low-energy photons and 1 MeV neutrons as well as high-energy photons and 1 MeV neutrons in synergistic damage. Additionally, transient current under simultaneous neutron and photon irradiation was calculated using COMSOL software. Simulation results indicate that by adjusting the number of photons, it is feasible to simulate the transient electrical characteristics of high-energy photons utilizing low-energy photons for synergistic damage. Hence, a novel characterization method, combining laser simulation and neutron sources, is developed to test the transient electrical characteristics of Si BJT with synergistic damage.

Comparative Analysis on Aluminium Interdigitated Electrode Surface: Influence of Ionic Strength and Electrolytes Changes

The field of generating surface thin films in sensing applications is emerging, and the incorporation of thin film technology into sensor development for enhanced sensing is becoming increasingly significant in various industries such as healthcare, environmental monitoring, and food safety. However, in order to achieve higher specificity in biosensing, advances in nanomaterial biofunctionalization are crucial. This research focuses on the fabrication and characterization of nanobiosensors with surface modification using two different sensing materials: zinc oxide and gold nanorod nanocomposites. The aim of this study was to enhance the sensing capabilities of nanobiosensors by incorporating surface modification with different sensing materials. The fabrication of nanobiosensors involved using silicon as the base material and conventional photolithography to fabricate aluminium interdigitated electrodes with three different structures and gap sizes. AutoCAD software was utilized to create three different photo masks with varying gap sizes. Physical characterization of the fabricated ALIDEs was conducted using atomic force microscope, high power microscope, scanning electron microscope, and 3D-profilormeter. The electrical characterization of the ALIDEs was performed using a Keithley 6487 picoammeter. I-V measurements were conducted on bare ALIDEs as well as surface modified ALIDEs with zinc oxide and gold nanorod. I-V measurements were also performed for pH scouting. The I-V measurements on bare ALIDEs revealed that ALIDEs modified with gold nanorod conducted the least current compared to ALIDEs modified with zinc oxide. Furthermore, the ALIDEs modified with gold nanorod were found to be stable under various electrolytes environments after undergoing pH scouting.

Interference voltage measurement and analysis of cardiac implants exposed to electric fields at extremely low frequency.

Objective.The possibility of interference by electromagnetic fields in the workplaces with cardiac implants is a concern for both individuals and employers. This article presents an analysis of the interference to which cardiac implants are subjected under high-intensity electric field at the power frequency.Approach.Evaluations of interference were conducted by studying the induced voltages at the device input in the real case study and the substitute study, and establishing an association between them with the equivalence factor F. A funnel-shaped phantom, designed for in vitro testing and representing the electrical characteristics of the locations where cardiac implants are installed, was used in the substitute study. A measuring system was implemented to measure the induced voltage at the device input under high intensity electric fields.Main results.The induced voltages obtained in the experimental measurements align with the findings of the numerical study in the phantom. By applying the equivalence factors derived between the real case study and the substitute study (2.39 for unipolar sensing; 3.64 for bipolar sensing), the induced voltages on the cardiac implants can be determined for the real case using the substitute experimental set-up.Significance.The interference voltages on the cardiac implants under EF exposures at low frequency were experimentally measured with detailed description. The findings provide evidence for an analysis method to systematically study the electromagnetic interference on the cardiac implants at low frequency.&#xD.

Modification of PEDOT:PSS thin film properties using pyridine-based solid additive for optoelectronic applications

Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) is one of the most promising hole transport layers that is widely used in high-performance optoelectronic devices. However, the hygroscopic nature and acidity of PEDOT:PSS is known to cause degradation in devices and decrease their performance. In this study, a new pyridine solid additive, 2,3-dihydropyridine (2,3-DHP) was incorporated into the PEDOT:PSS solution to improve its characteristics. A low-temperature solution-based spin-coating device was utilized to produce the thin films. From the results, the PEDOT:PSS@2,3-DHP (1 wt%) exhibited excellent optical characteristics. It also provided informative and controlled morphology when it was annealed at 100 °C, suggesting that PEDOT:PSS@2,3-DHP has a potential advantage in photovoltaic (PV) devices. Moreover, in the photodetection experiment utilizing LED of 380 nm, PEDOT:PSS@2,3-DHP showed a higher photocurrent response when compared with pristine PEDOT:PSS. It also significantly reduced sheet resistance and achieved superior electrical conductivity. Interaction between the 2,3-DHP, PEDOT, and PSS chains altered the mechanical properties of the PEDOT:PSS, leading to the modification in structural and electrical characteristics. Overall, these findings highlight the importance and applicability of PEDOT:PSS@2,3-DHP in a wide range of optoelectronic devices.

Ce3+ doped zinc manganese ferrite nanoparticles: Tuned mechanical, dielectric and radiation shielding characteristics

In this paper, the impact of cerium (Ce) additives on the structural, electrical and radiation attenuation characteristics of cerium zinc (Zn)- manganese (Mn)-based spinel nanoferrite, named ZMCeF-nanoferrite was investigated. Our investigation involved a thorough examination of the morphology and distribution of the ZMCeF-nanoferrite utilizing HR-TEM analysis, which revealed showcasing the distinctive spherical morphology of the nanoparticles along with observations of their aggregation tendencies. These findings are ascribed to the heightened magnetic interactions between the ZMCeF-ferrite nanoparticles. The ZMCeF5 nanoferrite demonstrates an optimal dielectric constant value compared to the free Ce ferrite composition, exhibiting an enhancement ratio of 109 %. Additionally, it showcases optimal conductivity, with an upgrading ratio of 780 %, and minimal loss, with an enhancing ratio of 3.5 %. Moreover, the elastic moduli of the ZMCeF5 sample exhibited a marked increase as the Ce content increased. Upon examining the mass attenuation coefficient (MAC) of ZMCeF-nanoferrite across three energy regions, we note a trend of increased MAC values corresponding to higher Ce additions. In contrast, the half-value layer (HVL) values decrease as Ce additions increase. Comparing the HVL values of the current ZMCeF-nanoferrite with those of selected radiation shielding material, we find that HVL of the ZMCeF-nanoferrite exhibits smaller values. These findings present promising prospects for optimizing spinel nanomaterials for use in radiation shielding applications.

Utilization of jarosite and manganite mineral as raw material to fabricate metal-oxide composite film for gas sensor application

This study explores the utilization of Indonesia’s abundant geological resources, specifically jarosite and manganite minerals, to develop composite films for ethanol gas sensing applications. With jarosite’s Fe2O3 composition and manganite’s diverse applications in manganese oxide minerals, these minerals serve as promising raw materials. Building on prior research that employed Fe2O3 and manganese oxide composites, our focus lies in creating a cost-effective composite film comprising iron, manganese, and zinc oxides to enhance ethanol gas sensing capabilities. The fabrication process involves mineral extraction through a precipitation method, followed by composite synthesis and film formation using a screen-printing technique. Analysis of the resulting composite film’s morphological and crystal structure through SEM and XRD machines provides porosity and crystallinity characteristics. Examining electrical characteristics reveals the gas sensor behavior, emphasizing sensitivity and response in an ethanol environment. This study aims to contribute to gas sensor technology advancements, leveraging Indonesia’s geological wealth, promoting cost efficiency, and addressing critical aspects of sensitivity in gas sensor applications.

Comprehensive investigation into the influence of oxygen vacancies on the ferroelectric properties of spin coated bismuth ferrite thin films

Bismuth ferrite (BFO) is a prime candidate for room-temperature magnetoelectric coupling and multiferroic applications. The rhombohedral R3c phase of BFO is the source of many properties, but the phase purity and oxygen vacancies are still the biggest obstacles to its real-world application. Considering these facts, the present work investigates the effects of oxygen vacancies on the functional properties through manipulation of drying temperatures of spin-cast films, especially at temperatures around 280 °C, where both the secondary phase and oxygen vacancies are prevalent. One of the biggest sources of oxygen vacancy is bismuth volatilisation, and our work deals with the situation head-on, uncovering the effect of bismuth volatilisation on functional properties. The structural properties were studied using x-ray diffraction (XRD), and deeper insights into the surface topography of the samples were obtained using AFM imaging. The electrical and dielectric characteristics help distinguish and analyse the samples in terms of the presence of resistive switching. PUND studies were performed to determine the ferroelectric properties of the samples. A fifty percent reduction in the oxygen vacancies in the presence of secondary phases was observed when compared with the phase-pure sample, as shown by the XPS analysis. Deeper insights were provided into the valence band spectra by first-principles studies. This work shows that phase purity may not be the singular condition for enhancing functional properties, and fine-tuning the presence of secondary phases and oxygen vacancies may be the way forward. The ferroelectric polarisation in one of the samples exhibits a notably higher value when using chemical solution deposition methods, making it a promising candidate for memory devices.