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 Journal of ElectroceramicsJournal Prestige (SJR): 0.427 Citation Impact (citeScore): 1Number of Followers: 0      Hybrid journal (It can contain Open Access articles) ISSN (Print) 1573-8663 - ISSN (Online) 1385-3449 Published by Springer-Verlag  [2469 journals]
• Structure–property correlation in (1-y)Bi0.9Ca0.1FeO3-(y)PbTiO3 (0.0
< y < 1.0) solid solutions

Abstract: Abstract The importance of using divalent ion doped BiFeO3 ceramics in-place of pure BiFeO3 informing solid solutions with other ferroelectric materials is emphasized. The phase stability for the (1-y)Bi0.90Ca0.10FeO3-(y)PbTiO3 system in the complete composition range show occurrence of interesting structure modulations. The changes in the crystal unit cell also seem to have significant effects on the microscopic structure. The SEM studies indicate the formation of more than one type of grains in the system. Such coexistence of one type of grains is found to show relaxor type characteristics both in dielectric and magnetic properties. Suitable models are used to explain the origin of the observed bi-relaxor type characteristics. The low temperature ac-magnetic studies suggest stabilization of a predominant spin-glass type characteristics in samples with 0.30 < y < 0.50.
PubDate: 2022-05-03

• Oxygen vacancy-induced Al2TiO5 –based multifunctional ceramic
composites: Electrochemical and optical properties

Abstract: Abstract In this study, Al2TiO5 –based multifunctional ceramics were prepared using the spark plasma sintering method within a temperature range of 1573–1773 K. The influence of the sintering temperature on the microstructure, phase composition, and electrochemical and optical properties of the Al2O3-TiO2-Al2TiO5 ceramics was evaluated. The results showed that ceramic composites sintered at T = 1773 K possessed the lowest porosity and optical reflectance (5%) in the visible, UV and infrared wavelength ranges. They were characterized by an average crystallite size of approximately 35 nm and the bandgap of 2.2 eV. Considerable changes in the electronic band structure and density of states inside the bandgap lead to enhanced charge carrier separation and reduced charge transfer resistance (RCT = -1.7).
PubDate: 2022-04-25

• Influence of calcination parameters on the microstructure, magnetic and
hyperthermia properties of Zn-Co ferrite nanoparticles

Abstract: Abstract Magnetic nanoparticles (NPs) are of interest for use in magnetic hyperthermia. To achieve high efficient NPs as a heating agent, it is important to know the effect of processing parameters on the synthesis, microstructure and magnetic properties of NPs and their relationship with the systems’ specific loss power (SLP). In the present study, zinc cobalt ferrite NPs were precipitated using the co-precipitation method, and calcined at 550, 650 and 750 °C for 1 and 2 h. Then to evaluate their hyperthermia properties, ferrofluids of neat and PEGylated NPs (NPs@PEG) were studied. The analysis of X-ray diffraction (XRD), field emission electron microscopy (FESEM), vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FTIR), zeta potential and transmission electron microscopy (TEM) were used to characterize the NPs. It was found that the processing parameters had a significant effect on the microstructure, magnetic and hyperthermia properties of the synthesized NPs. With increasing the time and temperature of calcination, particle size and magnetic properties like anisotropic constant, magnetic moment and saturation magnetization increased too. Hyperthermia results showed that the synthesized NPs at 550 °C for 2 h produced more heat than the other samples. It was also found that the concentration of NPs had a great influence on the heat generated by the prepared ferrofluids. Ferrofluids containing 5 mg/ml of NPs synthesized at 550 °C for 2 h had the highest heating efficiency such that the SLP value of NPs and NPs@PEG was 139.3 and 83.6 W/g, respectively.
PubDate: 2022-04-05

• Study on growth, optical and dielectric properties of ‘Nd’ DOPED
NBT-BT (0.94(Na0.5Bi0.5tio3)-0.06batio3) relaxor ferroelectric single
crystals

Abstract: Abstract The present work describes the effect of Neodymium (Nd) in the NBT-BT (0.94Na0.5Bi0.5TiO3-0.06BaTiO3 (NBT-BT (94/06)) + xNd (x = 0, 0.4, 0.6, 0.8, 1.0 wt%)) crystal grown by flux method. As the concentration of the Nd increases beyond 0.4 wt%, homogeneity of the solution is lost and the multinucleation was observed. Color of the crystal changed from yellow to muddy green and size of the crystals were reduced due to the incorporation of Nd in NBT-BT. Nd completely diffused into the NBT-BT lattice, hence no secondary phase formation was observed in XRD. But the peaks were shifted towards the higher angle side due to the shrinkage of NBT-BT lattice. Optical properties of the crystals are studied using UV–visible and photoluminescence spectra. Except 0.4 wt% of Nd, for all other concentration emission at 1064 nm was observed in the PL spectra. Effect of Nd in dielectric constant and the relaxor properties are discussed in detail.
PubDate: 2022-04-01

• Precursor synthesis and properties of iron and lithium co-doped cadmium
oxide

Abstract: Abstract Lithium and iron co-doped cadmium oxide Cd0.9(Li1-xFex)0.1O (x = 0.1, 0.3, 0.5, 0.7) with NaCl structure has been synthesized using formate of the composition Cd0.9(Li1-xFex)0.1(HCOO)2·2H2O as a precursor. The NMR spectroscopy results demonstrate that the structure of lithium-doped cadmium oxide appears to have impurity centers only of one type. All the synthesized samples show a metal-like conductivity as indicated by the growth of their electrical resistance with temperature increasing in the interval 78–330 K. The study of the magnetic properties of the Cd0.9(Li1-xFex)0.1O samples at 5 and 300 K revealed that they are ferromagnets, whose saturation magnetization increases with the iron concentration both at low and room temperature reaching the maximal values in the samples with a Li and Fe concentration of 3 and 7 at.%, respectively. An enhancement of the iron concentration in Cd0.9(Li1-xFex)0.1O from x = 0.5 to x = 0.7 leads to an abrupt growth of the magnetization from 0.30 to 1.94 emu/g at 5 K and from 0.16 to 1.03 emu/g at 300 K. Iron doping with a simultaneous reduction of the lithium concentration also results in an increase of the band gap. The properties of these compounds are explained on the basis of first-principles calculations of their band structure.
PubDate: 2022-03-31

• Preparation and dielectric properties of La doped NBCCTO ceramics

Abstract: Abstract CaCu3Ti4O12 ceramics have great dielectric constant, excellent temperature stability and good frequency stability. However, due to high dielectric loss, its practical application in engineering is hindered. In this paper, Na0.25Bi0.25LaxCa0.5-3x/2Cu3Ti4O12 (NBLCCTO) ceramics were prepared by solid phase synthesis. The effects of sintering temperature and La content on dielectric properties of NBLCCTO ceramics were studied. The results show when the sintering temperature is 1030℃ and La content is 0.05, NBLCCTO ceramics show better dielectric properties. Its dielectric constant has εr = 22,231 at 1 kHz and its dielectric loss is 0.0546 at 10 kHz. Appropriate doping of La can lead to grain refinement and enlarge specific surface area of grain boundary, thus increasing resistivity and reducing dielectric loss. Therefore, NBLCCTO ceramics have lower dielectric loss than Na0.25Bi0.25Ca0.5Cu3Ti4O12 (NBCCTO).
PubDate: 2022-03-25

• High energy storage, structure evolution and dielectric properties of
complex perovskite solid solution (1-x) NaNbO3-xBi (Zn2/3Nb1/3) O3

Abstract: Abstract NaNbO3-based lead-free ceramics show great potential in energy storage and piezoelectric applications due to the antiferroelectric and ferroelectric features. However, pure NaNbO3 usually shows lossy hysteresis loops because of the metastable antiferroelectric phase at room temperature. In this work, Bi(Zn2/3Nb1/3)O3 was introduced into NaNbO3 to modulate the phase structure, dielectric, and energy storage properties. The addition of Bi(Zn2/3Nb1/3)O3 changed the phase structure from orthorhombic to pseudo-cubic, decreased the grain size from ~ 20 μm to ~ 1 μm, shifted the temperature of dielectric peak from 360℃ to room temperature, and led to much-reduced polarization hysteresis and improved breakdown strength. With the addition of 9 mol% Bi(Zn2/3Nb1/3)O3, the maximum recoverable energy density of 3.3 J/cm3 was achieved under 33.5 kV/mm. These results provide a feasible route to design and fabricate new NaNbO3-based energy storage ceramics.
PubDate: 2022-02-21
DOI: 10.1007/s10832-022-00279-6

• The vibro-acoustic analysis of a matching layer attached on a 1–3
piezoelectric composite transducer

Abstract: Abstract A well-designed matching layer attached to a transducer is an effective method to obtain broad bandwidth. In practical applications, the optimal material parameters and geometric parameters for the matching layer are required to be calculated precisely. In this paper, we propose a fluid–structure interaction model for vibro-acoustic analysis of the transducer. An analytical solution to determine the electrical impedance of a transducer with a matching layer immersed in water is derived. The influence of matching layer on the performance of the transducer is demonstrated clearly. To verify the proposed model, a 1–3 piezoelectric composite transducer with a matching layer according to the our proposed model is fabricated. Consequently, the theoretical model we proposed can accurately predict the electrical impedance of the transducer with a matching layer. According to the model, the optimal thickness and acoustic impedance for the matching layer to expand the conductance bandwidth of the transducer can be figured out accurately. In addition, our proposed model also provides a reference for designing a transducer with a matching layer.
PubDate: 2022-02-15
DOI: 10.1007/s10832-022-00277-8

• Structural, morphological and electrical properties of new type Dy doped
Ca6-xNa2Y2(SiO4)6(OH)2 hydroxyapatite compound synthesized by co –
precipitation method

Abstract: Abstract In this study Dy3+ doped Ca6-xNa2Y2(SiO4)6(OH)2 (x = 0 – 0.05 mol%) hydroxyapatite compound was synthesized by co – precipitation method. The structural analysis reveals that the prepared compound has single phase hexagonal structure with space group P63/m. Scanning electron microscopy images show that the grains have irregular morphology and the grain size lies between 120—800 nm. The dielectric and electrical conduction studies of hydroxyapatite compound was done over a wide range of frequency (102 – 105 Hz) and temperature (500C – 5000C) respectively. Dielectric measurement shows that orientational and space charge polarizations are the dominant polarization mechanisms. Complex impedance and electric modulus spectroscopy analysis shows that ionic conduction is the presiding conduction mechanism. Nyquist plots depict the contribution of grains rather than grain boundaries in the conduction phenomena. A.C conductivity analysis shows that hydroxyl (OH)− and oxygen (O−2) ions were the main charge carriers responsible for conduction phenomena in hydroxyapatite compounds.
PubDate: 2022-01-03
DOI: 10.1007/s10832-021-00274-3

• Influence of preparation method on phase formation, structural and
magnetic properties of BiFeO3

Abstract: Abstract Nanocrystalline BiFeO3 was synthesized utilizing two distinct techniques: auto-combustion and ceramic. A unique auto-combustion process employing glycine as a fuel has been used to synthesize single-phase BiFeO3 nanoparticles. Well mixed metal nitrates combust, producing BiFeO3 nanoparticles, which crystallize in a rhombohedral perovskite structure. The average particle size of 16 nm was estimated using Rietveld refinement of the X-ray diffraction data. The X-ray diffraction data for the solid-state prepared sample shows the formation of BiFeO3 with the same rhombohedral perovskite structure with an average particle size of 101 nm with additional secondary phases corresponding to Bi2Fe4O9/Bi2O3 and Bi25FeO39. By increasing the sintering time Bi2Fe4O9/Bi2O3 phase disappeared after 3 h of heating and reappeared again after 5 h of sintering. The changing of sintering time was not able to reduce the Bi25FeO39 formation. The TEM estimated average particle size confirms the XRD analysis. M(H) hysteresis loop shows a G-type magnetic structure. Due to the small particle size, the periodicity of canted spins was broken, and the magnetization of the auto-combustion prepared sample is approximately eight times greater than the ceramic prepared one. The importance of pure phase BiFeO3 came from its potential applications in sensors, data storage, spintronics devices, and reports of greatly enhanced ferroelectricity in epitaxially strained thin films.
PubDate: 2022-01-03
DOI: 10.1007/s10832-021-00276-1

• Fabrication and properties of 1–3 connectivity epoxy resin modified
cement based piezoelectric composite

Abstract: Abstract The 1–3 connectivity epoxy resin modified cement based piezoelectric composites were developed to meet the requirement of concrete structural heath monitoring. The piezoelectric ceramic volume fraction on piezoelectric, dielectric and electromechanical coupling properties of the composites were discussed. The results showed that the relative permittivity of the piezoelectric composites increases linearly with increasing the PZT piezoelectric ceramic volume fraction, but the dielectric loss of the piezoelectric composites is a little bit larger than that of the PZT ceramic. The piezoelectric strain constant d33 of the piezoelectric composites is mainly contributed by PZT ceramic and is in proportion to PZT volume fraction, however, the piezoelectric voltage constant $${g}_{33}$$ show the opposite variation. When PZT volume fraction decreases to 27.7%, $${g}_{33}$$ value of the piezoelectric composites reaches to 75.0 (mV)·m·N−1. When PZT ceramic volume fraction is 62.33%, the thickness electromechanical coupling coefficient kt of the piezoelectric composites is the largest of 66.73%. The acoustic impedance Z of the piezoelectric composite is close to that of the concrete when PZT ceramic volume fraction is less than 44.44%.
PubDate: 2021-11-30
DOI: 10.1007/s10832-021-00275-2

• Magnetic and photocatalytic properties of CoFe2O4/Ni nanocomposites

Abstract: In this research, hard/soft CoFe2O4/Ni magnetic nanocomposite samples with different concentrations of Ni were successfully produced by a two-step mechanical alloying route. Single-phase CoFe2O4 (CFO), having the average particle size of 35 nm, saturation magnetization of 71 emu/g, and bandgap energy of 2.6 eV was synthesized via the mechanical alloying method. A mixture of as-synthesized CFO and 10, 30 and, 50 wt. % Ni powder has been severely milled to prepare magnetic nanocomposite samples. The effects of different Ni content on the characteristics of the nanocomposite samples have been investigated. FESEM images showed that the ductile nickel powder particles get flattened after 1 h milling, whereas the brittle CFO particles get fragmented by increasing milling time to 10 h. The single-phase-like hysteresis loop, and the switching field distribution curves alongside the simultaneous enhancements of maximum energy product and remanence reflect the presence of exchange spring phenomenon in the nanocomposite samples. Also, the diffuse reflectance spectroscopy (DRS) analysis evidence the reduction of bandgap energy for 10 wt.% Ni containing nanocomposite sample from 2.44 to 2.15 eV on increasing the milling time from 1 to 10 h. Under the optimum photocatalyst operating conditions, the CFO/10 wt% Ni sample exhibited the highest photocatalytic activity of 93.6% for methylene blue (MB) degradation in comparison with the cobalt ferrite sample. Eventually, the detailed kinetic and mechanism to describe the improvement of the photocatalytic performance were suggested. Graphical abstract
PubDate: 2021-11-18
DOI: 10.1007/s10832-021-00271-6

• Band gap tuning of oxygen vacancy-induced Al2O3-TiO2 ceramics processed by
spark plasma sintering

Abstract: Abstract Optical and photocatalytic applications of Al2O3 and TiO2 ceramics are limited, especially under visible light, due to their wide bandgap; so, this parameter plays an important and even decisive role in these applications. In the present study, Al2O3-TiO2 ball milled powders were sintered by spark plasma sintering (SPS) at 1573 K. The products were characterized using XRD, SEM, UV–Vis and electrochemical methods. The results indicated effective improvement in the light absorbing capability of the composites (up to 95%) under visible light and the decrease of the band gap down to 2.2 eV owing to the increase of oxygen vacancies, which was, in turn, due to the reduced atmosphere of the sintering process. In addition, formation of a new phase (Al2TiO5) during sintering greatly affected the absorption of Al2O3-TiO2 composites in the visible light region due to the increase in the fraction of the charge carrier separation centers. Photo-luminescence spectroscopy also showed that tialite formation could be effective in improving the charge separation efficiency.
PubDate: 2021-11-11
DOI: 10.1007/s10832-021-00273-4

• BaTiO3-based nanogenerators: fundamentals and current status

Abstract: Abstract Piezoelectric nanogenerators (PENG) collect energy from the environment and biomechanical movements and convert this mechanical energy into electrical energy. They have become an attractive alternative to traditional rechargeable batteries for providing electrical power low energy portable devices. As PENGs became the center of attention in robots, wearable devices, medical equipment, and many other fields, the development of piezoelectric materials has become mandatory. This review reviews the basic information, structure, properties, and preparation methods of Barium Titanate, one of the most important PENGs, its development in recent years, and the progress towards high energy generation.
PubDate: 2021-11-10
DOI: 10.1007/s10832-021-00266-3

• Characterization of anode supported micro-tubular solid oxide fuel cells
prepared by successive non-aqueous electrophoretic deposition

Abstract: Abstract In this study, micro-tubular solid oxide fuel cells (MT–SOFCs) were manufactured by successive electrophoretic deposition (EPD) in non-aqueous solvent. At first, stable suspensions of YSZ (Electrolyte), Ni/YSZ (anode) and LSM (cathode) in isopropanol were prepared. The EPD was performed on graphite rods under various voltages and times. The proper EPD condition was determined to prepare porous electrodes and dense electrolyte layers. The graphite rod was decomposed by heating at 900˚C and the resulting tubular thin films were sintered in air at 1350˚C. The microstructure of the sintered samples was studied by SEM analysis. The performance of the SOFC was investigated by electrochemical impedance spectroscopy. It was found that MT–SOFC with an internal diameter of 0.7 mm can be obtained via successive EPD. The maximum power density of the cell was 0.25 W/cm2at 850˚C.
PubDate: 2021-10-25
DOI: 10.1007/s10832-021-00272-5

• Back-to-Basics tutorial: X-ray diffraction of thin films

Abstract: Abstract X-ray diffraction (XRD) is an indispensable tool for characterising thin films of electroceramic materials. For the beginner, however, it can be a daunting technique at first due to the number of operation modes and measurements types, as well as the interpretation of the resultant patterns and scans. In this tutorial article, we provide a foundation for the thin-film engineer/scientist conducting their first measurements using XRD. We give a brief introduction of the principle of diffraction and description of the instrument, detailing the relevant operation modes. Next, we introduce five types of measurements essential for thin film characterisation: $$2\theta /\omega$$ scans, grazing-incidence scans, rocking curves, pole figures, and azimuth scans (or ϕ scans). Practical guidelines for selecting the appropriate optics, mounting and aligning the sample, and selecting scan conditions are given. Finally, we discuss some of the basics of data analysis, and give recommendations on the presentation of data. The aim of this article is to ultimately lower the barrier for researchers to perform meaningful XRD analysis, and, building on this foundation, find the existing literature more accessible, enabling more advanced XRD investigations.
PubDate: 2021-10-13
DOI: 10.1007/s10832-021-00263-6

• Improved electric insulation ability and ferromagnetic property in Nb2O5
doped BiFeO3-based multiferroic ceramics

Abstract: Abstract 0.675BiFeO3-0.3BaTiO3-0.025LaFeO3-x mol% Nb2O5 (x = 0–1.25) multiferroic lead- free ceramics, fabricated by conventional solid-state reaction, were studied to reveal the effects of Nb2O5 on the structural, morphology, dielectric, ferroelectric, magnetic and magnetoelectric properties of the BiFeO3-based ceramics. After the addition of Nb2O5, the crystal structure of as-prepared samples remained orthorhombic phase. The doping Nb5+ ion could be able to inhibit grain growth remarkably and suppress the creation of oxygen vacancies of this ceramics, which resulted in the improvement of electrical insulation by two orders of magnitude. The ferromagnetism was apparently enhanced with increasing content of Nb2O5, and the observed remanent magnetization Mr peaked at 0.022 emu/g for x = 1. Suitable amount of Nb2O5 could be beneficial to the dielectric properties, with the optimal x at 0.75, with dielectric constant εr of 918 at 100 Hz. The observed magnetoelectric coefficient αME suggested the existence of magnetoelectric coupling effect in these ceramics. The αME value almost decreased after adding Nb2O5, possibly due to the obvious degradation of ferroelectric behaviors.
PubDate: 2021-10-08
DOI: 10.1007/s10832-021-00267-2

• Crystallographic structure- and texture-dependent fracture behavior of

Abstract: Abstract The effect of crystallographic structure and texture on the fracture behavior of lead zirconate titanate (PZT) ceramics was investigated. PZT ceramics with Zr/Ti ratio of 45/55 (tetragonal, T), 52/48 (morphotropic phase boundary, MPB), and 60/40 (rhombohedral, R) were fabricated, and then textured using electric field and/or mechanical stress. Vickers indentation method was employed to characterize their fracture behavior. Results show that the unpoled specimen exhibits fracture toughness isotropy, with values of 1.24 MPa·m1/2, 1.07 MPa·m1/2, 1.17 MPa·m1/2 for T, MPB, and R, respectively. The textured specimen reveals fracture toughness anisotropy (FTA). The largest FTA was observed for the mechanically (M) poled specimens. Additionally, FTA for the MPB composition was larger than the T and R specimens. The crystallographic structure and texture dependent domain switching behavior, and the parameters of coercive stress and Young’s modulus measured by mechanical compression are used to explain the observed phenomena.
PubDate: 2021-09-29
DOI: 10.1007/s10832-021-00270-7

• Porous ceramics based on diatomite: Mechanical properties and evolution of
morphology after deformation

Abstract: Abstract The work is devoted to the study of the mechanical properties of porous ceramics based on diatomite, which has high porosity, adsorption capacity, weak thermal and acoustic conductivity, refractoriness and acid resistance. Based on the morphological analysis of the samples, the numerical value of the sample’s porosity was determined. The mechanical properties of the samples were determined by static and dynamic loading methods. The values of static and dynamic elastic moduli of the samples were experimentally measured. The research results showed that, for the material under consideration, at the initial stages of compression processes, the processes of elastic deformation are mainly realized with the subsequent transition to the region of plastic deformation. It was also found that for highly porous samples in the elastic deformation region, the manifestation of pressing processes is possible. In this work, the study of the dependence of the dynamic modulus of porous diatomite ceramics on porosity was carried out: a decrease in elastic moduli was recorded with an increase in the material porosity. A decrease in material porosity after deformation is found.
PubDate: 2021-09-29
DOI: 10.1007/s10832-021-00269-0

• Tailoring the multiferroic properties of BiFeO3 by low energy ions
implantation

Abstract: Abstract This work presents the implantation of various ions, such as Au+, As+, Ge+, Y+, and Co+, to modify the structural parameters, surface morphology, and multiferroic properties of BiFeO3 (BFO) ceramics. All the samples were synthesized using the solid-state reaction method. Significant variations in the structural, morphological, ferroelectric, and ferromagnetic properties of BFO were observed due to the implantation of various ions using 500 keV at ion fluence of ~ 3 × 1012 ions/cm2. X-ray diffractometer patterns showed structural distortion in the implanted samples. Scanning Electron Microscopy (SEM) images exhibited definite grain size variation over the surface due to mass transport. The X-ray Photon Spectroscopy (XPS) indicated the successful implantation of all ions and revealed the impact of Fe2+/Fe3+ concentrations in irradiated samples. The magnetic and ferroelectric loops revealed the improved ferroelectric/ferromagnetic behaviour of BFO due to implantations.
PubDate: 2021-09-24
DOI: 10.1007/s10832-021-00258-3

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