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There is a huge amount of pollution as well as the critical waste management issues create serious health problems caused by the lead-based ceramics for humans, marine organisms. Several countries are on a strict propaganda to implement the restrictions towards the utilization of lead as a candidate for device engineering. So now the focus shifted towards finding an alternative lead-free piezoelectric material which gives similar type of properties as compared to lead-based piezoelectric materials. In this report a polycrystalline ceramic having chemical formula Ba (Bi 0.9 Dy 0.1 ) Nb 2 O 9 (BBDNO termed further). The dielectric constant and loss of the ceramics have been examined for a frequency sweep 1 kHz to 1 MHz at different temperatures. The microstructure of the natural sample surface reveals that the presence of grain of various size and EDS spectra confirms all the elements are present without any impurity. The conductivity studies revealed that the experimental data follows the Jonscher's power law. The impedance spectroscopy suggests that the prepared sample has non-Debye type of relaxation. Further, the pellet was coated with silver electrode on opposite sides and utilized to harvest the biomechanical pressure imparted from finger tapping.

Polar perovskite materials have attracted extensive attention due to the coexistence of magnetic ground state and semiconductor band gap within the same material. For the first time triple perovskite Sr3Co2WO9 has been synthesized in the nanocrystalline form with an average crystallite size of 23 nm using a modified aqueous citrate sol-gel method. The crystal structure of Sr3Co2WO9 is cubic at the room temperature, space group Fm-3m with with lattice parameter a= 7.9073(6) Å. The formation of Sr3Co2WO9 was studied by cyclic voltammetry, UV/Vis spectroscopy and in situ X-ray diffraction method subsequently analysed by the Rietveld analysis. The detected hysteresis loops reveal ferrimagnetic ordering with Curie temperature of 144 K. The measured effective magnetic moment of 3 mB is close to the expected value for rarely observed intermediate spin S = 1 but can also be explained as a combination of HS (40 %) Co3+ and LS (60 %). The compound exhibits the semiconducting properties with the optical band gaps equal to 3.52 eV (indirect) and 3.76 eV (direct), respectively, calculated from UV/Vis absorption spectrum using the Tauc method. Semiconducting nature was also confirmed by AC conductivity measurements, which is between 10−5 and 10−4 Ω−1 cm−1. The frequency dependent dielectric constant was explained by employing the Maxwell-Wagner model. The frequency dependent AC conductivity follows the universal Jonscher’s power law. This material could be a good candidate for implementation as a constituent for devices where its semiconducting properties would be spin controlled.

A modified aqueous sol-gel reaction is used to synthesize a triple perovskite with a composition Sr3Co2WO9 (SCWO). The structural analysis conducted at room temperature reveals the presence of the cubic phase with space group Fm-3m. The microstructure of the as-synthesized SCWO particles shows a different size of particles depicting a polycrystalline nature. Triboelectrification is a trending and unique concept in energy scavenging methodologies with flexibility in choosing from a variety of materials. This paves the way to evolve eco-friendly triboelectric energy harvesters as a replacement for the limitation of batteries. The outstanding dielectric properties and low loss make triple perovskite a promising candidate for TENG. A triboelectric nanogenerator (TP-TENG) was designed, which operates in vertical contact separation mode generating an electrical response of voltage and current of 300 V and 2.2 μA, respectively, for 10 wt% polydimethylsiloxane-Sr3Co2WO9 (PDMS-SCWO) composite film. The power density of the rough surface TP-TENG was 30.5 μW/cm2, which is much higher than the power density of 5.5 μW/cm2 of plain surface TP-TENG. The positive and negative triboelectric layers of the TP-TENG were made up of aluminum and PDMS-SCWO composite film, respectively. Furthermore, the excellent flexibility and durability of TP-TENG make it suitable for sensing various gaits and information signaling (Morse code) in real-time applications, as well as for charging commercial capacitors.

The triboelectric nanogenerator (TENG) is a widely used energy-harvesting unit for self-power applications. The electrical output performance of the TENG could be significantly improved by ion implantation and explore new triboelectric materials beyond the conventional triboelectric series. In this present work, the phase pure hydrothermally synthesized ZnO particles, argon ion-implanted Kapton acted as a positive triboelectric layer while pure Kapton behaved as a negative triboelectric layer. The atomic force microscopy (AFM) and Kelvin probe force microscopy (KPFM) were performed to investigate the surface roughness and surface potential of the triboelectric materials utilized in vertical contact mode TENG (I-TENG, abbreviated further). The elemental mapping and X-ray photoelectron spectroscopy (XPS) results suggested successful Argon-ion implantation upon Kapton. Finally, the I-TENG device was subjected to various forces to systematically depict its electrical output responses and power up a wrist-watch and calculator.

Electroactivated disposable pencil graphite electrode (ePGE) was used for hesperidin detection with cv and dpv Electroactivation efficiency of the pencil graphite electrode (PGE) was examined with EIS and SECM. Enhancement of electron transfer kinetics after electroactivation was found. Hesperidin is irreversibly oxidized on ePGE (oxidation was the most pronounced at pH = 5.0). Linear dependence between the peak current and the hesperidin concentration from 5×10‐7 M to 1×10‐5 M was obtained. Determined LOD was 2×10‐7 M. Hesperidin was quantified in pharmaceutical formulation with ePGE and the results were in a good correlation with concentrations determined with HPLC‐DAD (R2 = 0.9462).

The ceramic-polymer composites were prepared by mixing 0.7Bi(Fe0.98Ga0.02)O3-0.3BaTiO3 (BFBTO) and poly(vinylidene fluoride) (PVDF), taken at various weight ratios 5, 10, and 15% processed by solvent-casting technique. The X-ray diffraction (XRD) spectra depict combined phases (α−, β− and γ−) of the PVDF and tetragonal phase of BFBTO. The surface morphology was examined by scanning electron micrograph showing the spread of lead-free BFBTO filler on matrix PVDF. The rise in filler content, in the PVDF matrix, enhances dielectric constant and remnant polarization. The Nyquist plot suggests the contribution of grain and grain boundary effect. The composite films shall be useful for various self-power sensors.

In this report, Ba1Bi1Cu1Fe1Ni1Ti3O12 (BBCFNTO termed further) ceramics were synthesized using a conventional ceramic processing route. The formation of multiple phases has been confirmed from by the XRD pattern at room temperature. The surface micrograph indicates the uniform distribution of grains with distinct grain boundary. The co-relation between the impedance and dielectric parameters was realized by using a phase sensitive meter over a good temperature and frequency range. The temperature- and frequency-dependent dielectric properties are linked to the conduction mechanism. The dielectric constant (K) and loss (tanδ) are increased sharply at high-temperature region, which is expected to be the onset of dipolar relaxation phenomena. The contribution of grain boundary (GBs) and grain (Gs) effects can be identified using the complex impedance spectroscopy. This synthesized material is investigated to model multifunctional devices.

Nowadays, much attention is paid for the development of lead-free complex or mixed metal oxides, which can be utilized for multi-functional devices. This communication provides the information on synthesis (by mixed oxide route) and physical properties (structural, electrical and ferroelectric) of the polycrystalline sample of Bi(Fe 0.9 La 0.1 )O 3 Analysis of the phase formation and basic crystal data of the material using X-ray diffraction (XRD) technique shows an orthorhombic symmetry with well-defined cell parameters. It has been shown that a small amount (10%) of La substitution at the Fe site of BiFeO 3 suppresses the impurity phase usually observed during phase formation of BiFeO 3 . The average crystallite size, calculated through applying Scherrer's technique, was found to be 68 nm. For the study of surface morphology (grain size and distribution) of the compound, the scanning electron microscope (SEM) was used. The grains of different dimension were found homogeneously distributed at the entire surface of the sample. The La substitution strongly affects the capacitive (dielectric) and resistive (electrical) characteristics of bismuth ferrite in a wide range of frequency and temperature. The contributions of grains and grain boundaries in the capacitive as well as in the resistive properties of the material at different temperatures and frequencies were studied by means of the impedance spectroscopy technique. This study has provided numerous useful and interesting data which may find potential industrial applications.

In the present paper, fabrication and characterization (structural, electrical and ferroelectric properties) of a lead-free lanthanum (La) modified bismuth ferrite electroceramic having composition Bi(Fe0.5La0.5)O3 (BFLO) using various experimental techniques have been reported. BFLO has been synthesized by means of a high-temperature inter-diffusion of oxides method. This investigation mainly aims to correlate the phase formation and physical properties while the Fe-site of bismuth ferrite has partially been replaced by La. The surface micrograph shows the formation of the high dense ceramic sample. Analysis of data of various complex spectroscopies related to modulus and impedance exhibits the relaxation mechanism in this sample is of non-Debye type. The combined effect of grains and grain boundaries has been depicted from the Nyquist plot through the least-squares fitting of suitable circuit model along with the experimental data. The remnant polarization and coercive field decreases as temperature rises which was discerned from the ferroelectric loop obtained at different temperatures. The existence of ferroelectric nature in the sample was postulated from the polarization versus electric field plot.

Purpose of Study: The present work shows studies of some physical properties of a gallium (Ga) modified lead zirconate titanate (PbZrTi)O3 with molar ratio Zr/Ti::48/52 (i.e., near morphotropic phase boundary (MPB)) having (Pb0.92Ga0.08)(Zr0.48Ti0.52)0.98O3 (PGaZT-8) as a chemical composition. Methodology: The material was fabricated employing high-temperature mixed oxide route. Main Finding: X-ray diffraction spectra suggest a distorted perovskite structure having two phases (tetragonal and monoclinic phases) with the substitution of small amount (2 and 4 wt %) of Ga in Pb(ZrTi)O3 (PZT). However, with higher concentration of Ga (6 and 8 wt %) in PZT, the multiphase perovskite structure is converted into an orthorhombic system with few impurity phase of Ti3O5. Analysis of field emission scanning electron micrograph (FESEM) of 8 wt% Ga modified PZT (PGaZT-8) shows the uniform distribution but different dimension and shape of grains depicting high-density ceramic sample. In the dielectric studies no dielectric anomaly exists in the experimental temperature range (25-500oC) in PGaZT-8, which determines the substitution of 8 wt% Ga in PZT (in MPB region) is found responsible for the suppression or shift (towards higher temperature) of known ferroelectric phase transition of PZT. There is an enhancement of permittivity, loss factor and conductivity as Pb site of PZT is doped with Ga. Applications of study: This study is useful for the determination of the characteristics of the prepared material as a base for device fabrication. Novelty of the Study: It is a systematic study of correlation of structural properties with the physical properties. It helps to understand the relaxation and conduction mechanism of PGaZT-8 using impedance and modulus spectroscopy.

The present article provides the detailed study of the effect of strontium on the structural, microstructural, dielectric and electrical characteristics of calcium copper titanate (i.e. Ca0...

The polycrystalline samples having chemical formula 0.7(BiGdxFe1−xO3)−0.3(PbTiO3) (x = 0.0, 0.05, 0.10, 0.15 and 0.20) were fabricated by using high temperature mixed oxide route. The X-ray diffrac...

The paper presents the fabrication and characterization of structural and electrical properties of an electronic composite of three perovskites: BaTiO3, BiFeO3 and CaSnO3 in a fixed ratio of 80/13/07 (i.e., 0.80(BaTiO3)-0.13(BiFeO3)-0.07(CaSnO3) (referred as BTO-BFO-CSO-7)) using standard experimental techniques. Analysis of room temperature X-ray diffraction spectra helps to determine the crystal system and unit cell dimensions (lattice parameters) of the sample. The dielectric and impedance spectroscopy was used to study the resistive (impedance, complex electrical modulus and electrical transport properties) and insulating (dielectric) characteristics of the prepared electronic material at various frequencies (102–106 Hz) and temperatures (20–450 °C). Study of the Nyquist plot confirms the presence of temperature dependent bulk (grain) effect only and negative temperature coefficient resistance in the BTO-BFO-CSO-7 composite. Analysis of conductivity spectra reveals that the charge transfer by hopping contributes to the electrical transport process. The dielectric relaxation of the sample is studied using complex modulus spectra. This study also helps to understand the mechanism of the electrical transport process, which depicts a non-Debye type of conductivity relaxation. The magnetic hysteresis loop (M − H) shows a remanent magnetization of 0.031 emu/g.

A perovskite sample of a chemical formula Ca0.8Ba0.2Cu3Ti4O12 (CBCTO-20) ceramic has been fabricated by a low-cost ceramic technology. The structural analysis reveals that the studied compound has ...

The paper mainly reports the effect of NaNbO 3 (as a doping material) on the structural (crystal data and microstructure), dielectric (permittivity, dissipation of energy) and electrical (impedance, modulus, and conductivity) characteristics of BiFeO 3 forming a solid solution of Bi .8 Na .2 Fe .8 Nb .2 O 3. By analysis of the room temperature X-ray diffraction data, the formation of pure-phase material and its crystal data were obtained. The comprehensive studies of dielectric parameters (relative dielectric constant (e r ), and tangent loss (tan δ) were measured in a wide range of temperature (25–450 °C) and frequency (1 kHz-1 MHz). The surface morphology, obtained with a gold-coated pellet sample, exhibits the high density of the sample. The frequency-temperature dependence of conductivity follows the Jonscher’s Universal Power law. The electrical behavior of the compound has been studied using complex impedance and modulus data. The effect of grain and grain boundary on the capacitive and resistive properties of the material has been studied from complex impedance spectroscopy.

A lead-free solid solution of two ferroelectrics, bismuth sodium titanate and barium titanate, of a composition 0.96(Bi0.5Na0.5TiO3)-0.04(BaTiO3) (termed as BNT-BT-4) was prepared by a standard low-cost ceramic technology. The phase analysis of the solid solution, carried out using X-ray diffraction pattern, shows a major tetragonal phase and a minor impurity phase at room temperature. The surface morphology of the prepared system showed the formation of the high-density sample. The phonon mode statistics, width location and intensity of the peaks were analyzed by Raman spectroscopy. The temperature-frequency dependence of dielectric parameters (permittivity and tangent loss) and AC conductivity were analyzed. The apparent activation energy of BNT-BT-4 was evaluated with help of AC conductivity data. The effect of grain on the capacitive and resistive properties has been studied using an impedance spectroscopy technique. The decrease in the value of grain resistance on rising temperature shows the semiconductor or negative temperature coefficient behavior of the material. Based on an analysis of complex modulus spectrum, the conduction mechanism in the material has been suggested. As BNT-BT-4 shows a remarkable temperature independent relative dielectric properties and low tangent loss, it is a potential candidate for devices.

In the present communication, studies of some physical properties (i.e., crystal data, permittivity, impedance, electrical cobnduction and magnetic) of a multiferroic material with a chemical composition (SmLi)1/2(Fe2/3Mo1/3)O3 have been reported. Thermogravimetric analysis of the compound, prepared by cost effective ceramic technology processing, was executed to check the mass loss as well as the required decomposition temperature of the ingredients. An analysis of X-ray spectra or pattern suggests that the crystallization phase or cystal system of the compound at room temperature is orthorhombic. The broad studies of dielectric properties {relative dielectric constant (er), and tangent loss (tan δ)} display their independence of temperature and frequency in the rage of (30–375 °C) and (1 kHz–1 MHz) respectively. The impedance spectroscopic technique has provided a considerable significant information regarding the grain, grain boundary contribution within the sample and relaxation mechanism of the compound. The occurrence of negative temperature coefficient behaviour (NTCR) is depicted by the further analysis of impedance parameters. The frequency–temperature dependence of conductivity follows the Johnson’s power Universal law. The Arrhenius plot (i.e., variation of electrical conductivity with temperature) is used to calculate the activation energy. Analysis of magnetization (M–H) loop shows weak ferromagnetism of the compound. The material possesses significantly high magnitude of magnetoelectric coefficient of 3.0 mV Cm− 1 Oe− 1.

In the present paper, the effect of addition of a small amount (8 wt%) of barium titanate (BT) on electrical properties of bismuth sodium titanate (BNT) forming a solid solution of a composition (0.92)(Bi 0.5 Na 0.5 TiO 3 )+(0.08)(BaTiO 3 ) (BNT-BT-8) has mainly been reported. The solid solution of BNT-BT-8 was prepared by a cost effective and standard mixed-oxide method. Preliminary structural analysis using X-rays diffraction pattern and data showed the existence of two phases; orthorhombic (major) and tetragonal (minor impurity/secondary) phase. Analysis of scanning electron micrograph and energy dispersive spectrum of the pellet sample reveals the formation of high density with homogeneously distributed grains of varying dimension. The locations, phonon modes statistics, width and intensity of peaks of Raman spectra of BNT-BT-8 was analyzed by Raman spectroscopy and provided some data on molecular structure of the material. The effect of temperature and frequency on some ferroelectric characteristics of the material were studied. The frequency-temperature dependence of electrical characteristical such as impedance of the material was studied by impedance spectroscopy. The electric conductivity follows the Arrhenius equation and provided activation energy at different frequency. The dielectric and impedance spectroscopy suggest the existence of a non-Debye relaxation mechanism in the material.

This study presents a systematic investigation on the NiO-Mg mechanochemical reduction process to form in-situ ferromagnetic NiO-Ni-MgO nanocomposites and utilize them as positive triboelectric layers in the fabricated triboelectric nanogenerator (TENG) devices for harvesting biomechanical energy in real-life applications. The structural and microstructural analyzes reveal a near-complete NiO reduction with three phases of face-centered-cubic structured nanocomposites. The magnetic study exhibits a robust ferromagnetic behavior. The correlative fractions of NiO and Ni phases eventually determine the overall structural and magnetic behavior of the nanocomposites. The coexisting ferromagnetic Ni and antiferromagnetic NiO phases determine the overall magnetic anisotropy induced ferromagnetism. The high temperature magnetization studies confirm the induced ferromagnetism caused by the higher Ni contents due to the NiO reduction. The nanocomposite, acting as a positive triboelectric layer, is successfully utilized for TENG device application, which helps to convert the accessible waste mechanical energy into suitable electrical energy. The fabricated TENG device with an area of 2 cm × 2 cm delivers the voltage of 35 V, an electrical current of 130 nA and a power density of 0.72 µW/cm2 at 108 Ω load resistance. The demonstration of biomechanical energy harvesting using the fabricated TENG devices provides ways to utilize the ferromagnetic nanocomposite as a positive triboelectric layer, suitable for several energy harvesting device applications in daily life.

The polycrystalline sample of CaSnO3 modified BiFeO3–BaTiO3 with a composition 0.85BaTiO3–0.1BiFeO3–0.05CaSnO3 (hereafter BTO–BFO–CSO-5) was fabricated by a cost effective ceramic technology. The crystal system and unit cell dimensions of the prepared system were obtained by analyzing the room temperature X-ray spectra or pattern, and found to be an orthorhombic phase. The scanning electron micrograph shows the formation of the high-density ceramic sample. Resistive (impedance, modulus and electrical transport) and insulating (dielectric) properties of the system have been obtained using dielectric and the impedance spectroscopy at various frequencies (102–106 Hz) and temperatures (25–450 °C). The Nyquist plots exhibit the presence of the effect of grains in the prepared sample. The electrical transport properties of the material can be explained with the help of charge transfer by hopping process. The complex electrical modulus plot is used to determine the dielectric relaxation. The frequency dependence of conductivity plot follows the universal Jonscher power law.

Triboelectric nanogenerators (TENG) can convert the waste mechanical energy into useful electrical energy and act as a sustainable power source for micro/nanoelectronics. The utilization of advanced surface designs and materials compositions can further enhance the performance of TENGs. A single-electrode mode TENG with cilia microstructures (C-TENG, abbreviated further) was fabricated from polydimethylsiloxane-carbonyl iron (PDMS-Fe) composite by using a simple and fast magnetic field-guided method and its energy harvesting performance was evaluated. The structures, electrical properties, and surface roughness were compared between the flat and cilia-formed PDMS-Fe composites. The single-electrode mode TENG based on PDMS-Fe 10 wt% gives an open-circuit voltage of 70 V, the peak to peak current output of 250nA, and the power density of 2.75 μW/cm2 at 30 MΩ. Further, the ion injection was applied to the PDMS-Fe 10 wt% composite films using an antistatic gun, and it doubles the voltage output of the device. C-TENG can convert biomechanical energy (i.e. wind blowing and finger tapping) into an electrical output. In addition, the powering of a calculator was showed by charging a commercial capacitor using a bridge rectifier circuit.

This study presents a multiunit hybrid piezo-triboelectric nanogenerator (HNG), utilizing both the triboelectric and piezoelectric effects, constructed from Bismuth Titanate, Bi4Ti3O12 (BiTO)/polydimethylsiloxane (PDMS) composite films through a simple and cost-effective fabrication technique. The BiTO samples synthesized by a mixed oxide route crystallize in the orthorhombic symmetry, as confirmed by the Rietveld refinement of the structural data. The temperature- and frequency-dependent dielectric spectra elucidate the colossal dielectric properties of BiTO, originating from the combined effects of interfacial polarization, hopping polarization, and extrinsic electrode effect. The colossal dielectric BiTO leads to the amplification of internal polarization, providing enhanced output performance of the HNG device. As a result, the HNG devices exhibit multiple folds improvement in terms of power density compared to individual PDMS-BiTO composite-based PENG and TENG devices. Subsequently, a new design of device structure comprising a multiunit HNG device is constructed with the help of a 3D printed structure and a ball, delivering the voltage and current output of 300 V and 4.7 μA, respectively. Finally, the HNG device is utilized for biomechanical energy harvesting and powering various electronics like LEDs, a calculator, and a wristwatch.

A great impact of the multifunctional or multiferroic materials on device applications has gained tremendous attention from scientific research groups in the field of materials science. The multiferroic materials bear superior properties of alternating the ferroic orders in a pre-designed way to match the device specifications. Materials in which there is a coupling between the primary ferroic orders (ferroelectric, ferromagnetic, ferroelastic) are termed multiferroics. This paper shows the investigation of a room temperature multiferroic material bearing a chemical composition LaFeO3 (LFO) also known as rare-earth orthoferrites. The particles of LFO are synthesized employing mixed oxide processing with heat treatment. The Rietveld analysis of the material shows that the LFO crystallizes having an orthorhombic symmetry and Pbnm space group. The complex impedance spectra indicate the distribution of relaxation time and non-Debye-type behavior. The dielectric parameters measured at various frequencies and temperatures suggest the formation of a colossal dielectric constant and low loss. The elemental analyses of the material show that there is no impurity present in the material. The pellet of the LFO arranged in a metal-insulator-metal arrangement is tested for gas sensing application. The LFO material has an excellent selectivity towards NO2 gas at relatively low operating temperatures ranging from 50 °C to 300 °C along with a sub-ppm limit of detection. A set of cyclic testing confirms that LFO can carry out stable and lengthy gas sensing operations while demonstrating outstanding adsorption and desorption characteristics. Such superior gas sensing properties and dielectric characteristics can pave the way toward the ultra-high sensitive gas sensors based on lead-free orthoferrites perovskites.

The laboratory waste produced in several parts of the world has scaled up the pollution and adverse effect on human health in the present era. The “3 R” (reduce, reuse, and recycle) scheme is adopted by many communities for efficiently recovering waste products and utilizing them for the production of energy. In the present work, the laboratory waste is collected and directly utilized for fabricating a laboratory waste-based triboelectric nanogenerator (LW-TENG) operating in vertical contact-separation mode. The substrate, electrode, and triboelectric layer are randomly selected from lab waste. The waste plastic petri dishes were extruded into thin filament wires for 3D printing of the substrate for the LW-TENG. The effective electrical output is generated by LW-TENG having a triboelectric layer plastic-glass delivering voltage of 185 V, current of 1.25 μA, and power density of 8.1 μW/cm2 across the load resistance of 500 MΩ. The positive and negative triboelectric layers are altered and the electrical output is systematically investigated. Additionally, the LW-TENG device is attached to various locations of the laboratory to demonstrate the energy harvesting from the mechanical motions. It is also utilized for demonstrating real-time applications that could be beneficial as a self-powered human tracking device (HSD) that tracks the location of the human during an emergency and self-powered exercise counter.

The additive manufacturing research confides in developing three-dimensional (3D) printing routes for the fabrication of devices with multifunctional materials in various interesting application areas such as self-healing, energy conversion/storage/harvesting, and sensing platforms. This paper reports the design optimization, fabrication, and characterization of a multi-axis pressure sensor with temperature compensation using fused filament fabrication (FFF) 3D printing of conductive carbon-based composites. Additive manufacturing offers a faster fabrication of complex structures with multiple properties such as electrical, mechanical, or thermal properties. The complex and costly metal printing can be neglected, as the 3D printing of a conductive polymer is a promising technology to utilize the electrical properties of the printed materials along with mechanical flexibilities. The present work focuses on the development of a multi-axis pressure sensor integrated with a temperature-sensing element. The pressure-sensing mechanism is based on piezoresistive behavior while temperature sensing relies on temperature-dependent resistance shift of the carbon composite. The pressure sensing part comprises a hollow structure to ensure mechanical deformation upon applied pressure while the temperature sensor is buried inside the housing material. Herein, the conductive three-dimensional printable polymer is synthesized by solution casting method with Polylactic acid (PLA), multi-walled carbon nanotubes (MWCNTs), and dichloromethane (DCM) solvent, which is transformed into filament for printing. The direction of pressure and magnitude of temperature can be evaluated separately by calibrating the responses of an applied force and temperature. Moreover, an integrated temperature sensor calibrates the shift in the electrical resistance of the pressure sensor due to the alteration in environmental temperature. The additive manufactured dual pressure and temperature sensor could open up broad applications such as human motion monitoring systems and force sensing.

The lead-free polycrystalline ceramic, barium titanate modified bismuth–sodium titanate 0.98 (Bi0.5Na0.5TiO3) + 0.02 BaTiO3 (BNT–BT-2) was synthesized by using a mixed oxide route at high temperature. The structural (crystal structure, microstructure, molecular structure), and electrical (dielectric constant and loss, impedance, conductivity) characteristics of the parent compound (Bi0.5Na0.5TiO3) have greatly been influenced by the addition of even a small amount of barium titanate in it. Preliminary structural study of BNT–BT-2 using X-ray diffraction data clearly shows the formation of a single-phase perovskite structure with the coexistence of hexagonal (major phase) and tetragonal (minor) phases. The existence of diffuse phase transtition and the relaxor behaviour in the material is confirmed by analysis of temperature-frequency dependence of dielectric parameters. The composition (0.98BNT − 0.02BT) of the material shows non-Ohmic conduction in its J–E characteristics. In this lead-free ceramic, permittivity anomalies are matched to modulus anomalies. The highlighted features are determined by structural phase transitions of the ferroelectric-like.

In the present paper, the gallium modified lead zirconate titanate ceramics with Zr/Ti = 48/52 (near the morphotropic phase boundary,MPB), having a chemical formula Pb0.98Ga0.02(Zr0.48Ti0.52)0.995O3, was synthesized by a mixed-oxide reaction method and sintered. Analysis of phase formation confirmed the co-existence of two phases (tetragonal and monoclinic symmetry) in the system. Microstructural study by scanning electron microscope showed a non-uniform distribution of large grains over the sample surface and presence of a small amount of micro-size pores. Modulus and impedance studies were carried out at various frequencies (1 kHz-1MHz) and temperatures (300-350?C) and showed the contributions of grains in capacitive and resistive properties of the material. The resistance and capacitance of the complex impedance plots are contributed by grains as observed from the Nyquist plots. The experimental data obtained from the Nyquist plot were implemented in an equivalent electrical circuit (RQC). The value of grain resistance and capacitance were obtained using fitting steps with precision at all temperatures. It is assumed that increase of dielectric constant at higher temperatures is due to the substitution of Ga+ ions at the Pb-site.

Gallium (Ga) modified lead zirconate titanate (PbZrTiO3) ceramics with Zr/Ti = 52/48 (i.e., near the morphotropic phase boundary) [i.e., Pb0.94 Ga0.06 (Zr0.48Ti0.52)0.985O3 = PGaZT-6] was fabricated by a mixed-oxide route at high temperatures. Based on determination of basic crystal data using X-ray pattern, single-phase orthorhombic phase of the prepared material obtained. Analysis of the field emission electron scanning microscopy images of the pellet (compacted) sample shows the homogeneous and densely packed grain distribution of varying shapes and size. The dielectric parameters of PGaZT-6 indicate the diffuse phase transition with non-relaxer characteristics of the material. The variation of these dielectric parameters with temperature and frequency of PGaZT-6 follows Jonscher’s universal power law. Thermal (50–500 °C) and electric field (1–1000 kHz) effect on electrical impedance parameters of PGaZT-6 (near MPB) have been analyzed using impedance spectroscopy (IS) technique. Structure-properties of the material has been correlated using this complex technique.

Complex perovskites have attracted extensive attention due to their fascinating physical properties and novel features owing to the coexistence of the ferro/ferri-magnetic ground state and semiconducting behavior in the single material. Herein, the triple perovskite Sr3Co2WO9 (SCWO) has been successfully synthesized for the first time in the nanocrystalline form with an average crystallite size of 23 nm using a high yield (81 %) aqueous citrate sol-gel method. At room temperature, the crystal structure of Sr3Co2WO9 is cubic, space group Fm-3m, with lattice parameter a= 7.9073(6) Å. The formation of SCWO triple perovskite was studied in situ by X-ray diffraction and subsequently analyzed by the Rietveld analysis. The detected hysteresis loops with non-zero remanent magnetization and rather large coercive field reveal ferrimagnetic ordering with a Curie temperature of 144 K. The measured effective magnetic moment of 3 μB is close to the expected value for rarely observed intermediate spin S = 1. It is found that the compound exhibits semiconducting properties with the optical band gaps equal to 3.52 eV (indirect) and 3.76 eV (direct), respectively, further confirmed by the determination of the AC conductivity, which in the measured temperature range (25 -500 °C at 1 kHz) lies within the interval from 10−5- 10−4 Ω−1 cm−1. The Maxwell -Wagner model is employed to describe the frequency dependent dielectric constant. The frequency-dependent AC conductivity follows the universal Jonscher’s power law. Since it possesses both magnetic and semiconductor properties, this material could be a promising candidate to use in devices where its semiconducting properties would be spin-controlled.

This paper shows a comparative study of sintered and thermally quenched Al2O3 substituted fused silica ceramics processed by colloidal suspension route. The structural analysis is performed using X-ray diffraction measurements. The natural surface micrographs present close packing of non-uniform shape of grains. The high permittivity and low loss are illustrated from frequency dependent permittivity. The impedance spectroscopy shows non-Debye type relaxation mechanism. The Nyquist plot shows the presence of only grain effect. The overlapping large Polaron tunnelling model is attributed from the conduction studies of both sintered and quenched samples.

Dense and stoichiometric $$\hbox {Ba}_{0.8}\hbox {Mg}_{0.2}(\hbox {Zr}_{0.1}\hbox {Ti}_{0.8}\hbox {Ce}_{0.1})\hbox {O}_{3}$$ (BMZTCO) ceramics have been synthesised and their excitation was experimentally evaluated by applying an electric field. The processed sample exhibits superior frequency-independent and temperature-dependent dielectric parameters. The prepared sample has combined the tetragonal and cubic phases of $$\hbox {BaTiO}_{3}$$ and $$\hbox {Ce}_{2}\hbox {O}_{3}$$ . The Bode plots suggest non-Debye type of relaxation mechanism and positive temperature coefficient-type behaviour. The excitation intensity reaches a peak when the driving frequency matches with the natural frequency of the prepared sample.

This paper presents the fabrication of a polycrystalline sample of the above electronic system by a mixed-oxide technique. The X-ray diffraction pattern show the evolution of perovskite phase (including some impurity phase). The rhombohedral symmetry and crystallite size of 42 nm were also found from the XRD. The distribution of grains in the microstructure suggests the formation of high density ceramics. The role of grains, grain boundaries and interface on resistive (impedance, electrical modulus and electrical transport) and insulating (dielectric) has been investigated over a wide range of frequencies (103–106 Hz) and temperatures (25–400 °C) using spectroscopy (dielectric, modulus and impedance) techniques. The Nyquist plot illustrates the presence of effects such as grain and grain boundary over selected temperatures. Analysis of conductivity spectra reveals that the electrical transport process of the material is influenced by charge transfer by hopping. The complex modulus spectrum also describes the dielectric relaxation of the material. The study of field dependent polarization reveals the existence of ferroelectricity in the material.

In the present work, the fused silica was fabricated using colloidal processing route. The fabricated samples were quenched (five time thermal cycling) and the results of the structural and electrical properties of the sintered sample and quenched sample have been studied and compared. The structural analysis confirmed the formation of the fabricated ceramics. The morphology of the sample suggested that there is close packing of the grains. The relaxation and conduction mechanism were analyzed using impedance and modulus spectroscopy. The dielectric parameters were inspected on varying temperature and frequency range. The impedance study showed the dependence of electrical properties on both frequencies and temperatures having corresponded with the morphology.

The bulk ceramics bearing chemical formula BiFeO3 and (BiLi)1/2(Fe2/3Mo1/3)O3 (abbreviated as BFO and BLFMO respectively) are synthesized using mixed oxide route. The physical properties (structural, dielectric, electric and magnetic) are tailored in Li and Mo co-doped BiFeO3. The phase evolution suggests that there is transformation from rhombohedral (pure BFO) to orthorhombic (BLFMO). Micro-structural suggests that due to co-doping the size of the grain is smaller than BFO. The dielectric properties of both BFO and BLFMO measure with an LCR meter varying the frequency (102–106 Hz) and temperature (30–375 °C). The leakage current decreases in BLFMO. The magnetic hysteresis loop owing weak ferromagnetism is depicted for Li and Mo co-doped BFO. The fabricated material will be base for various applications like filter and buffering.

Multiferroic materials predominantly formed by the coexistence of more than one primary ferroic ordering and also responsible for coupling in between these ferroic ordering. The objective of this paper is to develop multiferroic materials by coupling the ferroelectric property in BaTiO3 with magnetic property in rare earth orthoferrites (RFeO3, R- rare earth). In this report for the first time, we have introduced a room-temperature multiferroic material (1-x) BaTiO3- x ErFeO3, where x = 0.01, 0.02, 0.03, and 0.04 and its role in the development of internal hybrid configuration based multi-unit hybrid energy harvesting device (combining triboelectric and piezoelectric effect). Here the structural and electrical properties of multiferroic material are being investigated and analyzed. The particles were synthesized using a mixed oxide route, and the experimental structural, ferroelectric, and ferromagnetic properties were investigated systematically. Further, the multiferroic/PDMS piezo composite film acts as an active layer for multiferroic based piezo- tribo hybrid generator (MF-HG). The multi-unit MF-HG comprising of the composite (PDMS/ BTEFO) rough surface film generates a maximum electrical output of 320 V, 12 µA respectively. The magnetic property in this material is then used for detecting the stray magnetic field generated from the household appliances, proving that the MF-HG is a promising candidate as a self-powered magnetic field sensor.

Enhancing the performance of the nanogenerator is one of the main focuses in the field of nanogenerators and self-powered systems. The present manuscript shows the enhancement of electrical output by the fabrication of a hybridized nanogenerator by combining both triboelectric and piezoelectric nanogenerators (TENG-PENG). In addition, a surface modification process is employed by creating a porous composite film with polydimethylsiloxane (PDMS) polymer and barium titanate (BaTiO3) particles. The output generates through the surface potential of the composite film and piezoelectric property of the composite film upon its actuation. The positive and negative triboelectric layers are Aluminum and porous PDMS-BaTiO3 composite films. The PDMS-BaTiO3 (10 wt%) porous composite films-based device [designated as P-DMHG 4] generates the highest electrical output 280 V and 5.6 µA with the instantaneous area power density of 0.040 mW/cm2 at a load resistance of 100 MΩ. The P-DMHG device was capable of charging a capacitor which effectively drives the low power electronic devices and successfully demonstrated to act as a self-powered impact sensor. The impact sensor tested in real-time by placing at multiple positions on a bicycle helmet and checked upon mechanical impacts. The device shows a good sensitivity of 2.101 V/cm at a lower energy impact level. The tests prove that the device can be a potential candidate in the field of sensors and can employ the device for health care, industrial and sports applications soon.

The Aurivillius phase-based composition bearing chemical formula Bi4Pb2Zr2TiFeNbO18 (termed as BPZTFNO) was synthesized by a solid-state method. The structural analysis as obtained from the X-ray pattern has depicted an orthorhombic phase. The various size and morphology of grains are distributed throughout the natural surface as revealed from microstructure analysis. The dielectric and electrical study of the BPZTFNO is taken at a various sweep of frequency (1 kHz–1 MHz) and temperatures (25–400 °C). The ferroelectric-paraelectric phase transition is well illustrated from the temperature-dependent dielectric constant. The complex impedance analysis suggests the association of grain effect. The relaxation of non-Debye nature is shown in the impedance study. The formed sample is subjected to an electric field and further its excitation performance is examined suggesting its possible usage in devices.

The polycrystalline samples having composition Bi0.45Eu0.02Na0.45Pb0.1Zr0.048Ti0.952O3 (BNPZTE-2 abbreviated ahead), Bi0.41Eu0.04Na0.45Pb0.1Zr0.048Ti0.952O3 (BNPZTE-4 abbreviated ahead), Bi0.39Eu0.06Na0.45Pb0.1Zr0.048Ti0.952O3 (BNPZTE-6 abbreviated ahead) had been synthesised using the mixed oxide processing route. The prepared samples were found to be in single phase and crystallize in tetragonal structure. The surface morphology suggests the high density grain growth in all samples. The electrical behavior (dielectric, impedance, and modulus) of the prepared samples collected at various temperatures and frequencies. The value of activation energy had been evaluated from the temperature dependent conductivity plot. The grain and grain boundary contribution to the polarization process have been depicted from the impedance analysis. The parallel plate capacitor structure was proposed to unveil the influence of applied electric field on the excitation of samples. The prepared samples will find its application in the filter application (noise removal) or buffering circuit.

The 70% BiFeO3 (BFO) with 30% PbTiO3 composite has attracted attention of many researchers, as it falls under MPB (morphotropic phase boundary) region. The studied composites 0.7(BiSmxFe1−xO3)–0.3(PbTiO3) for x = 0.0, 0.05, 0.10, 0.15, 0.20 were synthesized through the conventional route of solid-state reaction. The crystallization, symmetry (rhombohedral), and structural confirmation of the composites have been made through X-ray diffraction technique. The surface morphology of the natural surface is observed employing scanning electron microscope. The dielectric, impedance, and conductivity study reveals the electrical behavior of the samples. The dielectric permittivity is seen to rise with the increase in doping concentration. The high value of dielectric constant (7390.5) found for 10 wt% doping concentration of samarium. The composites are found to show negative temperature coefficient of resistivity behavior in the temperature range (275–350 °C). The relaxation phenomenon is reflected through impedance plots. From these results, it may be concluded that this material may be used for different high-temperature applications.

In order to produce an ultra-high dielectric constant and low loss factor in a polycrystalline material of Sr+2-modified (concentration 15%) CaCu3Ti4O12 (i.e., Ca0.85Sr0.15Cu3Ti4O12, abbreviated as CSCTO-15) was prepared using a cost-effective solid-state reaction technique. Structural analysis using Rietveld refinement of the X-ray diffraction data has confirmed that the sample crystallizes in a cubic system with space group symmetry of Im3. Morphological/microstructural analysis of the natural surface of a pellet shows dense grain growth, with clearly visible grain boundaries. The dielectric relaxation mechanism of CSCTO-15 has been revealed by the detailed study of frequency- and temperature-dependent dielectric parameters (er and tan δ). Analysis of the frequency and temperature dependence of impedance and related parameters, collected by a complex impedance spectroscopic technique, has provided and estimated the contributions of grain, grain boundaries and electrode in the electrical process in the material. The activation energy at high temperatures has been calculated from the temperature-dependent ac conductivity plots at selected frequencies.

In the days of modernization, industrialization, technological world we find out a new method of steam production with help of coal. This state of act systems are manufactured over a range of 500 TPH.This boilers are highly efficient, multi coal firing capacity, less emission of so2 and nox gases, utilize high ignite cokes, petcoats,washery rejects. This survey paper is intended to comprehensively give an account of domain knowledge related to CFBC boiler. The authors touch upon the design changes which are introduced in the component levels in order to ease the operation, enhance the performance and to meet the regulatory compliance. In addition, salient correlations related to hydrodynamics, heat transfer and combustion are narrated to facilitate the control and system engineers to develop mathematical models using conservation of mass, energy and momentum equations.

In the present paper, the effect of gallium (Ga) substitution on structural, microstructural, electrical conductivity of Pb(ZrTi)O3 (PZT) in the morphotropic phase boundary (MPB) region (i.e., Pb0.96Ga0.04(Zr0.48Ti0.52)0.99O3 (PGaZT-4)) was investigated. Increased grain density increases the resistivity of the Ga-modified PZT system. Preliminary structural analysis using X-ray diffraction pattern and data showed the existence of two phases [major tetragonal (T) and minor monoclinic (M)]. Field emission scanning electron micrograph (FESEM) showed the distribution of spherical as well as platelet type grains with small pores. The behavior of dielectric constant with temperature of PGaZT-4 exhibited the suppression of the ferroelectric phase transition [i.e., disappearance of Curie temperature (Tc)]. The complex impedance spectroscopy (CIS) technique helped to investigate the impedance parameters of PGaZT-4 in MPB region in a wide range of temperature (250–500 °C) and frequency (1–1000 kHz) region. The impedance parameters of the material are found to be strongly dependent on frequency of AC electric field and temperature. The substitution of gallium at the Pb site of PZT generally enhances the dielectric constant and decreases loss tangent. The AC conductivity vs frequency (f = ω2π) in the region of dispersion follows the universal response of Jonscher’s equation. Enhanced resistive characteristics were observed for Ga-substituted PZT in comparison to the pure PZT, which was well ensured from the studies of electrical parameters, such as impedance and AC conductivity.

Some yttrium modified BiFeO3–PbTiO3 (BYFO-PT) compounds have been fabricated using a standard ceramic technology (solid-state route). The structural analysis from X-ray diffraction (XRD) data ensures the formation of the rhombohedral phase of the compounds. The prepared materials have major bismuth ferrite (70%) and lead titanate (30%) with few impurity phases. The materials are found to have a high dielectric constant and low tangent loss. The relaxation mechanism is identified from the peaks appearing in impedance and modulus curves. The materials show a negative temperature coefficient of resistance (NTCR) semiconductor type behavior in the temperature range of 250 °C–400 °C. In addition, grain and grain boundary effects are observed through the Nyquist plots. The activation energy (Ea) of the compounds is calculated from the slope of inverse temperature versus AC conductivity at the high-temperature range. The ferroelectric nature of the compounds is confirmed by electric field dependent polarization (PE-hysteresis) loops.