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The two primary physical methods for identifying lithium titanate, a negative electrode material used commercially, are X-Ray diffraction and Raman spectroscopy. Although there are many publications on this topic, they are focused mainly on chemistry, so there are still some points that require clarification from a physical and methodological point of view. Difference of experimentally observed and theoretically predicted Raman spectra was explained through a combination of experiments and computations. The work comprises experiments and computations to explain why there are different numbers of predicted and observed Raman-active bands. Our low-temperature study and the analysis of thermal shifts during heating led us to conclude that the approach with surplus bands is advantageous and we recommend using major F2g band shifts to estimate the sample heating. [ABSTRACT FROM AUTHOR]

A novel finding that the electrochemical performance of the commercial lithium titanate (Li4Ti5O12, LTO) can be significantly improved by using a novel current collector of CuI particles modified copper foil is reported for the first time in this work. Firstly, a large number of particles with well-defined shapes were prepared on the commercial copper foil surface via a very simple soaking process, in which the soaking solution contained only CuSO4, H2SO4 and [Bmim]I. As indicated by the XRD and XPS measurements, the particles observed on the surface of the copper foil were identified as CuI particles. That is, CuI particles modified copper foils (denoted as CuI/Cu) were successfully prepared at room temperature. CuI/Cu prepared in the presence of 0.4, 0.6 and 0.8 g of [Bmim]I were nominated as CF (copper foil) a, b and c, respectively. Inconceivably, as compared to the conventional LTO electrode, the LTO electrodes assembled using the newly prepared CFs exhibited a significantly improved electrochemical performance, i.e., all as-prepared CFs showed an evident promoting effect on the electrochemical performance of the traditional LTO electrodes. For instance, the initial discharge capacity (DC) of the LTO electrode assembled using CF b (called electrode b) at 0.2 C was 307 mAh g−1, which was about 1.86 times higher than that of the LTO electrode prepared using the conventional copper foil current collector (165 mAh g−1). Particularly, as the applied current rate was as high as 10 C, the DC value of electrode b (117 mAh g−1), even after 100 cycles, was still about 2.54 times that of the traditional LTO electrode (46 mAh g−1). In this preliminary work, a new method for preparing CuI particles was developed, along with a novel approach to significantly improve the electrochemical properties of the commercial LTO electrode. The method did not require any strong oxidants or reducing agents, nor did it demand any additional energy expenditure during the preparation of CuI particles. Moreover, the approach did not require any changes in the assembly procedure for the LTO electrodes being studied. This work was very meaningful for the development of the CuI-related research field as well as for the electrochemical performance improvement of LTO-based lithium-ion batteries (LIBs). [ABSTRACT FROM AUTHOR]

Sb-modified lithium bismuth titanate Li0.5Bi0.3Sb0.2TiO3 is prepared following the mixed oxide method. The development of a new compound with a single-phase orthorhombic crystal structure is approved from the XRD analysis at environmental temperature. The electrical behavior like dielectric and electrical conductivity are analyzed in a wide temperature as well as frequency range by the impedance analyzer, which exhibits that these properties effectively depend on frequency and temperature. The ac conductivity versus temperatures plots obeys the Arrhenius relation and confirm the presence of the mixed type of conductivity process like space charge conductivity created from oxygen ion vacancies, ionic-polaronic conductivity, and so on, in the sample. Ac conductivity versus frequency spectra is as per Jonscher's Universal Power law. [ABSTRACT FROM AUTHOR]

In this paper, detailed studies of effect of small amount of manganese substitution (at the zirconium site) on the structural, micro-structural, and electrical characteristics of lead zirconate titanate of Pb(Zr0.35–xMnxTi0.65)O3;x = 0, 0.02, 0.06, 0.10 (PZMT)) have been reported. The materials were prepared by using standard ceramic technology. The formation of the compounds and their basic crystal data have been studied through X-ray diffraction (XRD) method. The crystallite size and lattice strain of the compounds, evaluated from Scherrer's and Hall Williamson (H-W) equations, is found to be in the range of 40–50 nm and 11 × 10−4 to 50 × 10−4, respectively. Microstructures of different magnifications, revealing the surface nature of the compounds, have been recorded by field emission scanning electron microscope (FESEM). Effect of Mn+4 ions on electrical behavior (electrical impedance (Z*), electrical modulus (M*), conduction and relaxation phenomenon) of PZMT systems, over wide range of temperature and frequency, has been studied. [ABSTRACT FROM AUTHOR]

The structural, dielectric and transport properties of modified Bismuth Sodium Titanate (BNT) are reported. Mn and Sr-modified BNT (Bi0.35Na0.35Sr0.3Ti0.9Mn0.1O3) was synthesized by a solid-state reaction route. Structural analysis based on Rietveld refinement of X-ray diffraction data confirms the single-phase characteristic without change of hexagonal crystal structure with R3C space group of BNT. The dielectric characteristics of the modified BNT are recorded in the frequency range of 20 Hz to 1 MHz at temperatures of 50 °C and 200 °C. Using the frequency-dependent, real and imaginary parts of the dielectric constant, ϵ′(ω)-ϵ″(ω) dipolar and hopping conduction-based carrier polarization properties are discussed. The dipole parameters such as relaxation time, static and high-frequency dielectric constant etc. are estimated by using Cole-Cole relaxation model. [ABSTRACT FROM AUTHOR]

Crystal structure and Dielectric properties investigation of lead-free Bi0.35Na0.25Li0.1Sr0.3TiO3 (BNLST) composite is reported. The required solid solution was synthesized using oxides and carbonates via the solid-state reaction method. The stoichiometrically weighed and mixed powder was calcined at 800 °C for 12 h, and the pellets were sintered at 1250 °C for 2 h. XRD measurements confirm the formation of single-phase rhombohedral perovskite structure and the crystal structure was refined using the X'Pert High-score plus software. The full-width half maxima of the XRD peak was used to compute the average crystallite size employing the Debye-Scherrer, Williamson-Hall, and Halder-Wagner techniques. The BNLST's dielectric measurements were performed as a function of temperature at five distinct frequencies in the range of 100 Hz–1 MHz. The phase transition temperatures are shifted toward room temperature with the doping of Li and Sr. The diffuseness parameters of the phase transition, the a.c. electrical conductivity and the activation energy are estimated for the BNLST composite. [ABSTRACT FROM AUTHOR]

In this study, calcium titanate (CaTiO3) doped (0, 15, 25 and 35%) polyaniline (PANI) composites in the presence of dodecylbenzene sulphonic acid (DBSA) were successfully synthesized by the means of in-situ emulsion polymerization of aniline monomer. The structural, morphological and optical characterization of as-prepared composites were determined using X-ray diffraction (XRD), field effect scanning electron microscopy, Fourier-transform infrared spectroscopy, UV–vis analysis, and electronic conductivity was determined using two-point probe method. The structural analysis confirms that PANI–DBSA is amorphous, but sharp peaks present in XRD patterns in composites are of crystalline nature. The morphological study reveals efficacious integration of CaTiO3 particles into the PANI–DBSA matrix. Further, the integration of CaTiO3 remarkably reduced the optical bandgap (2.7–2.2 eV) by making composites with PANI–DBSA. Room temperature alternating current conductivity was found to obey universal power law and correlated barrier hopping was found most appropriate model to describe the sample's charge transport mechanism. With the increasing wt% of CaTiO3, the dielectric permittivity and loss both varied according to the interfacial polarization law of Maxwell–Wagner. Moreover, the I–V graphs showed augmented electrical conductivity of composites with an increase in CaTiO3 particle content than that of pure PANI–DBSA. This is a simple way by which PANI–DBSA/CaTiO3 composites having low optical bandgap, high electrical conductivity and permittivity may be fabricated for a widespread technological application. [ABSTRACT FROM AUTHOR]

The doped Pb(Zr0.52Ti0.48)O3 system with Nb5+ and Sr2+ were obtained by solid state reactions. The influence of nature of dopants on structural and microstructural properties were analyzed by XRD and SEM techniques and were also investigated the obtained dielectric and piezoelectric properties. The XRD analyzes and the SEM images highlighted the obtaining of homogeneous tetragonal structures, of the perovskite type. The physical (ρa), dielectric constant (ɛr) and piezoelectric (kp) properties of the doped PZT systems were investigated. The Nb5+ doped Pb(Zr0.52Ti0.48)O3 system presented the ɛr = 488 and kp = 0,52. Sr2+ substitution for Nb5+ doped Pb(Zr0.52Ti0.48)O3 reduced the Curie temperature (from 420°C to 360°C), increased the dielectric constant at 1180, and also decreasing the kp (0,39). [ABSTRACT FROM AUTHOR]

Oxygen-deficient perovskites (PbTi1−xFexLiyO3−δ, x = 0–0.25, y = 0.15) were prepared by gel combustion technique. This study presents the effect of Fe3+ and Li+ on the morpho-structural and electrical properties of ceramics. Two structural behaviors have been identified, depending on the Fe3+ amount. At low Fe3+ concentrations (3.7%), the variation of the cell parameters is given by the tetragonal change toward cubic phase while at higher levels (>15%) the variation of the cell parameters comes mainly from Fe3+/Ti4+ ionic radii differences. Fe3+ doping at Ti sites creates oxygen and titan vacancies in order to compensate the Ti4+ charge. Introduction of oxygen vacancies reduces progressively band gap energy from 3.28 to 2.63 eV. ICP-OES measurements show that Pb and Ti are lower than theoretical formula which it generates supplementary contributions to the oxygen deficiency. Addition of Fe3+ and Li+ leads to an increase of lattice micro-strains from 17.07·10−4 up to 24.44·10−4, improving ionic conduction. Moreover, DFT calculation shows that the lattice distortion tends to decrease with the increase of the Fe concentration, in agreement with the XRD. Based on BET analysis, the pore diameter decreases from 56.9 to 16.6 nm with the increase of iron amount and is correlated with the relative densities that increase from 82.0 to 91.27%. According to EIS investigations, activation energy varies between 0.632 and 0.950 eV, showing that the conduction in perovskite ceramics is based on double ionized oxygen vacancies. The highest conductivity at 500 °C was obtained for samples doped with 15% Fe and 25% Fe (2.4 × 10−3 S·cm−1), sintered at 750 °C. [ABSTRACT FROM AUTHOR]

The development of triboelectric nanogenerators (TENGs) has experienced rapid advancement in the past decade. In the present study, ethylene vinyl acetate (EVA) polymer and lead zirconium titanate (PZT) are taken as the host materials. The EVA–PZT elastomer composites are fabricated using different weight percentages (2.5%, 5.0%, 7.5%, and 10.0%) of PZT in EVA by solvent casting. The X‐ray diffraction investigation of these films reveals the presence of the PZT material and the formation of composites. TENGs have the potential to revolutionize energy harvesting and provide a sustainable energy source for a variety of applications. The electrical output performance of the single‐electrode‐mode‐based TENG is examined. The maximum output of 60 V and 165 nA is produced by the EVA–PZT 7.5 wt%/Al‐based TENG device. Further, TENG is used to power devices and gather biomechanical energy. [ABSTRACT FROM AUTHOR]

We probed the structural modifications and electronic behavior of composites obtained from the admixture of a biphasic titanate ceramic system (Na2Ti3O7/Na2Ti6O13) with a poly(o-methoxyaniline, POMA) matrix. The composites were obtained by the addition of Na2Ti3O7/Na2Ti6O13to a POMA matrix in mass concentrations from 0 to 35%. The sodium titanates were synthesized by means of sonochemistry, while the polymer was obtained by conventional chemical polymerization. The structural analysis carried by XRD, FTIR and UV-Vis indicated mostly the presence of POMA, though the titanates could be identified in the composites with higher concentration. The XRD diffractograms showed narrow reflections that could be correlated to the Na2Ti6O13 phase and hydrogen titanates, whose presence indicates a process of partial substitution of H+ for Na+ ions. While the thermal degradation of the polymeric chains starts near 150 °C, the thermogravimetric and differential thermogravimetric (TG/dTG) analysis revealed that the presence of sodium titanates enhances the thermal stability of the composites. Finally, the addition of the biphasic ceramic to the composite increases the electrical resistivity drastically, from ≈ 102 Ω cm in the pure POMA to ≈ 104 Ω cm in the 35% composite. [ABSTRACT FROM AUTHOR]

We probed the structural modifications and electronic behavior of composites obtained from the admixture of a biphasic titanate ceramic system (Na2Ti3O7/Na2Ti6O13) with a poly(o-methoxyaniline, POMA) matrix. The composites were obtained by the addition of Na2Ti3O7/Na2Ti6O13to a POMA matrix in mass concentrations from 0 to 35%. The sodium titanates were synthesized by means of sonochemistry, while the polymer was obtained by conventional chemical polymerization. The structural analysis carried by XRD, FTIR and UV-Vis indicated mostly the presence of POMA, though the titanates could be identified in the composites with higher concentration. The XRD diffractograms showed narrow reflections that could be correlated to the Na2Ti6O13 phase and hydrogen titanates, whose presence indicates a process of partial substitution of H+ for Na+ ions. While the thermal degradation of the polymeric chains starts near 150 °C, the thermogravimetric and differential thermogravimetric (TG/dTG) analysis revealed that the presence of sodium titanates enhances the thermal stability of the composites. Finally, the addition of the biphasic ceramic to the composite increases the electrical resistivity drastically, from ≈ 102 Ω cm in the pure POMA to ≈ 104 Ω cm in the 35% composite. [ABSTRACT FROM AUTHOR]

SrTiO3 is a well-known photocatalyst with various applications, such as antibacterial agents, self-cleaning surfaces, and water and air conditioning. With the increased environmental pollution, SrTiO3 is one of the most studied perovskite photocatalysts, exhibiting pronounced photocatalytic activity for removing chemical pollutants and water splitting. In the present work, pure Strontium titanate (ST) nanoparticles were successfully prepared using high-energy ball milling and Pechini techniques and characterized by X-ray diffraction (XRD), thermal gravimetric analysis (TGA), Fourier Transform Infrared spectroscopy (FTIR), scanning and transmission electron microscopy, respectively. Structural parameters were evaluated by Rietveld refinement analysis from XRD data, which confirmed the cubic system of SrTiO3 with Pm-3 m space group. Scanning electron microscope results showed that ST1 samples consisted of agglomerated and irregular-shaped structures between 20 and 40 nm, and in ST2, the particles were round-shaped and had an average size of 150 nm. The obtained nanoparticles were used for photocatalytic methylene blue (MB) degradation, and synthesis methods' influence on catalytic activity was investigated. The photocatalytic studies examining the decoloration of MB dye reveal the function of smaller particles in increasing the rate of reactions. The degradation rate constant of MB on the ST1 (Pechini-synthesized sample) and ST2 (high energy ball milled sample) is 0.0145 and 0.0112 min−1, respectively. The better photocatalytic activity of the ST1 demonstrated 93% degradation of dye under the solar light simulator. The photocatalytic reaction data provided well a first-order kinetic model. [ABSTRACT FROM AUTHOR]

La‐ and Sn‐cosubstituted lead zirconate titanate (PbLaZrSnTiO3) ceramics are synthesized using a solid‐state reaction route. These PbLaZrSnTiO3(PLZST) ceramics in pure form are found to exist in dual phase (Cc+P4mm) and single phase (Cc) depending on the amount of La/Sn cosubstitution. PLZST ceramics exhibit thin P–E loops with enhanced polarization when measured at 393 K. Olsen cycle method is used to estimate the pyroenergy harvesting abilities of the samples under study. The estimated maximum energy storage density for PLZST (50/30/20) ceramics at 393 K is 1.16 J cm−3 [efficiency (η) > 96%]. The PLZST ceramics exhibit a remarkable hardness of 9.08 GPa. These results indicate that PLZST ceramics with excellent multifunctional properties are potential candidates in the field of electroceramic devices. [ABSTRACT FROM AUTHOR]

A report on optical and structural investigations of Mn4+‐activated (ZnxMg1–x)2TiO4 red phosphors by X‐ray diffraction, photoluminescence (PL), and electron paramagnetic resonance methods is provided. The phosphors of Mg2TiO4, Zn2TiO4 and solid solutions (ZnxMg1–x)2TiO4 (x = 0.25, 0.50, 0.75) with manganese content of 0.1 mol% are synthesized at temperatures in the range of 800–1200 °C via solid state reaction. Formation of solid solutions of inverse spinel structure demonstrates the features similar to both the Mg2TiO4 and Zn2TiO4, i.e., decomposition of the (Zn,Mg)2TiO4 on the (Zn,Mg)TiO3 and MgO and separation of the secondary ZnO phase, respectively. These processes depend on the composition of solid solution and sintering temperature, and for some regimes, the single‐phase phosphor can be obtained. The largest intensity of Mn4+ red PL is found in the Mn‐doped (Zn0.25Mg0.75)2TiO4 phosphor sintered at 1100 °C and it is 2 times larger than those in similar Mn4+‐activated Mg2TiO4 phosphor. The differences in the PL intensity of the phosphors of solid solutions are explained by different PL thermal quenching as well as by competing processes of Mn incorporation in +2 and +4 charge states in zinc–magnesium titanate crystal lattice. [ABSTRACT FROM AUTHOR]

This manuscript examines the mechanism of strain-coupling in a multiferroic composite of mesoporous cobalt ferrite (CFO), conformally filled with lead zirconate titanate (PZT). We find that when the composites are electrically poled, remanent strain from the piezoelectric PZT layer can be transferred to the magnetostrictive CFO layer. X-ray diffraction shows that this strain transfer is greatest in the most porous samples, in agreement with magnetometry measurements, which show the greatest change in sample saturation magnetization in the most porous samples. Strain analysis shows that porosity both accommodates greater lattice strain and mitigates the effects of substrate clamping in thin film strain-coupled composites. [ABSTRACT FROM AUTHOR]

This manuscript examines the mechanism of strain-coupling in a multiferroic composite of mesoporous cobalt ferrite (CFO), conformally filled with lead zirconate titanate (PZT). We find that when the composites are electrically poled, remanent strain from the piezoelectric PZT layer can be transferred to the magnetostrictive CFO layer. X-ray diffraction shows that this strain transfer is greatest in the most porous samples, in agreement with magnetometry measurements, which show the greatest change in sample saturation magnetization in the most porous samples. Strain analysis shows that porosity both accommodates greater lattice strain and mitigates the effects of substrate clamping in thin film strain-coupled composites. [ABSTRACT FROM AUTHOR]

The properties of the potential matrix of the REE–actinide fraction of high-level radioactive waste have been studied. A sample containing 2 wt % of curium was obtained by sintering at 1400°С from a charge with the (Nd,Cm)4Ti9O24 composition. The sample was studied by the conventional XRD method. Its stability in water was determined according to the standard procedure (90°C, periodic change of solution). Contrary to the preliminary experiments with Sm (a Cm imitation) the sample consisted of perovskite-like Nd0.667TiO3 titanate and a small amount of Ti3O5 instead of the (Nd,Cm)4Ti9O24 titanate phase. The reason for the discrepancy is probably associated with the reducing conditions during the synthesis of the curium-containing sample, which led to the formation of (Nd,Cm)0.667TiO3 and Ti3O5 instead of the expected phase (Nd,Cm)4Ti9O24. From the change in the X-ray diffraction patterns over time and from the data of leaching experiments, the radiation resistance of the sample and its corrosion resistance (leaching rates of elements) in water were determined. [ABSTRACT FROM AUTHOR]

A direct quantification of a structural in-depth composition in the lead zirconate titanate Pb(Zr,Ti)O3 thin films of morphotropic composition has been conducted using the newly available X-ray nano-pencil beam (i.e., beam size of 100 nm ×1 μm) diffraction approach. We tested two samples with different Zr/Ti chemical gradients. Here, we demonstrate the presence of a significant microstructural gradient between the rhombohedral and tetragonal phases through PbZrxTi1-xO3 (PZT) films with a 100 nm in-depth resolution. The phase gradient extends over around 350 nm, and it is repeated through the PZT film three times, which corresponds to the number of thermal annealings. Moreover, this microstructural gradient is in agreement with the Zr/Ti chemical gradient observed by the secondary ion mass spectroscopy (SIMS). Indeed, the quantity of tetragonal phases rises in the Ti-rich zones as revealed by SIMS, and the quantity of rhombohedral phases rises in the Zr-rich zones. We also demonstrated a huge difference in the in-depth phase variation between the two tested samples. The gradient free sample still contains 4.7% of phase variation through the film and the amplified gradient contains 9.6% of phase variation through the film. Knowing that the gradient free sample shows better electric and piezoelectric coefficients, one can draw a correlation between the chemical composition, crystallographic homogeneity, and electromechanical properties of the film. The more close the film is to the morphotropic composition and the more it is crystallographically homogeneous, the higher the piezoelectric coefficients of the PZT are. Finally, the adequate knowledge of phase variation and its relation to the fabrication technique are crucial for the enhancement of the PZT electro-mechanical properties. Our methodology and findings open up new perspectives in establishing a relevant quantitative feedback to reach an ultimate electro-mechanical coupling in the sol-gel PZT thin films. [ABSTRACT FROM AUTHOR]

Herein, the synthesis and characterization of zinc (Zn)‐modified lead zirconate titanate (PZT) at the morphotropic phase boundary (Zr/Ti = 48/52) (i.e., Pb1−xZnxZr0.48Ti0.52O3 [x = 0.0, 0.03, 0.06, and 0.09]) are reported. The materials are synthesized using a high‐temperature solid‐state reaction route. Room temperature X‐ray structural (Rietveld) analysis confirms the formation of single‐phase compounds in tetragonal symmetry. The detailed dielectric studies exhibit that the Curie temperature of the modified PZT is 451, 444, 443, and 442 °C for x = 0.0 (PZT‐1), 0.03 (PZT‐2), 0.06 (PZT‐3), and 0.09 (PZT‐4), respectively. The existence of ferroelectric property in the compounds is confirmed through the room temperature electric‐field‐dependent polarization hysteresis loops. It is found that PZT‐1 has the highest dielectric constant ≈4327 (at 1 kHz) at TC as compared with that of other compositions. The frequency–temperature‐dependent dielectric and electrical properties demonstrate the contribution of zinc in the conduction mechanism. The observation of grain and grain boundary contributions to the charge carriers, the negative and positive temperature coefficient of resistance (NTCR and PTCR) nature across TC, a controlled (lower) leakage current (≈10−11 to ≈10−13), and the piezoelectric property make the materials useful for several applications. [ABSTRACT FROM AUTHOR]

Ceramic samples of lead zirconate titanate doped with lanthanum at the morphotropic phase boundary (PLZT 1.0/53/47) exhibit ferroelastic phase transition in the range from 135 to 150 °C. The study used structural analysis (XRD and Raman spectroscopy) and variation of dielectric and piezoelectric characteristics with temperature to analyze the ferroelastic and ferroelectric phase transition in PLZT. Measurements of X-ray diffraction patterns with temperature in the range from room temperature to 500 °C made it possible to monitor the evolution of the crystalline phases present in the sample, with a mixture of rhombohedral and tetragonal phases and initial concentrations of approximately 40 and 60%, respectively, as well as the evolution of the cell parameters and crystallite size. All techniques applied in this study showed the presence of phase changes in the temperature range from 135 to 150 °C, which is attributed to a displacive proper ferroelastic phase transition. This transition is associated with a decrease in the concentration of the rhombohedral phase and an increase in that of the tetragonal phase. Additionally, a transition at 350 °C is observed, which corresponds to the ferroelectric-paraelectric phase transition, coinciding with the results reported by Morgan Electro Ceramics for Type II Marine ceramics (PZT-5A). [ABSTRACT FROM AUTHOR]

Ceramic samples of lead zirconate titanate doped with lanthanum at the morphotropic phase boundary (PLZT 1.0/53/47) exhibit ferroelastic phase transition in the range from 135 to 150 °C. The study used structural analysis (XRD and Raman spectroscopy) and variation of dielectric and piezoelectric characteristics with temperature to analyze the ferroelastic and ferroelectric phase transition in PLZT. Measurements of X-ray diffraction patterns with temperature in the range from room temperature to 500 °C made it possible to monitor the evolution of the crystalline phases present in the sample, with a mixture of rhombohedral and tetragonal phases and initial concentrations of approximately 40 and 60%, respectively, as well as the evolution of the cell parameters and crystallite size. All techniques applied in this study showed the presence of phase changes in the temperature range from 135 to 150 °C, which is attributed to a displacive proper ferroelastic phase transition. This transition is associated with a decrease in the concentration of the rhombohedral phase and an increase in that of the tetragonal phase. Additionally, a transition at 350 °C is observed, which corresponds to the ferroelectric-paraelectric phase transition, coinciding with the results reported by Morgan Electro Ceramics for Type II Marine ceramics (PZT-5A). [ABSTRACT FROM AUTHOR]

Rare-earth Nd-doped lead zinc niobate-lead titanate (Nd:PZN-PT) and W-doped lead zinc niobate-lead titanate (W:PZN-PT) single crystals have been grown by self-flux technique and their dielectric, ferroelectric and piezoelectric properties have been investigated. Pure perovskite phases were observed, and lattice parameters were obtained by Rietveld refinement. Diffuse phase transition and frequency dispersive phenomena was observed in the dielectric peaks confirming the enhancement of relaxor behaviour for doped crystals. Variation of dielectric constant (ε), AC conductivity and piezoelectric charge coefficient (d33) as a result of doping is investigated in detail. From the hysteresis behaviour, it was evident that a simple domain switching mechanism was observed for doped crystals. [ABSTRACT FROM AUTHOR]

BaTi5O11 has been widely researched due to its unique microwave properties. Conventionally, it is challenging to obtain this compound as a single phase. The BaTi5O11 was synthesized via a co-precipitation technique using an aqueous solution of titanium(IV)(triethanolaminato) isopropoxide, barium nitrate and ammonia as precursors, which are stable in aqueous media. The phase evolution, purity, and structure were identified by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy analysis. The desired BaTi5O11 structure was obtained by calcination at 900 °C. Furthermore, the structure was characterized by TGA, FT-IR and Raman studies. The study showed that the particles were between 80 and 120 nm in size and the average crystallite size was determined from the Scherrer formula as 68.1 nm at 900 °C. [ABSTRACT FROM AUTHOR]

The present manuscript analyzes the dielectric relaxation and conduction behavior of samarium modified sodium bismuth titanate ((Bi (1-x) Sm x) 0.5 Na 0.5 TiO 3) ceramic prepared by solid-state reaction process. The X-Ray Diffraction acknowledges the presence of rhombohedral (R 3 c) phase in all composition with existence of small secondary phase for composition more than 2% of Sm doping. The dielectric relaxation and conduction mechanism of the compositions were studied through the impedance spectroscopy. The impedance values initially decrease up to doping level of x = 2% and increase with higher doping concentration. The Cole-Cole plot indicates the existence of grain and grain boundary resistance in all compositions. The conductivity enhances up to x = 0.02 and then reduces with doping concentration, and the conductivity spectra fitted with the modified Jonscher's power law indicates that small polaron hopping is the dominant phenomena for conduction in all compositions. The activation energy related to relaxation and conduction was obtained using the Arrhenius equation, and activation energy obtained specifies a reduction in oxygen vacancies with doping. The activation energy suggests that the oxygen vacancies associated with the short-range hopping is responsible for relaxation and doubly ionized oxygen vacancies are responsible for conduction. [ABSTRACT FROM AUTHOR]

A perovskite ceramic oxide, stannum (Sn) modified bismuth sodium titanate (BNT) (i.e., Bi0.5Na0.5Ti0.80Sn0.20O3) was synthesized by using a mixed oxide powder reaction route. Analysis of the X-Ray diffraction spectrum supports the polycrystalline nature of the compound with tetragonal symmetry. A phase change from the ferroelectric to paraelectric transition is observed at around 315 °C. The temperature and frequency dependence of dielectric properties and AC conductivity data of the material are analyzed. The Nyquist plots explain the effect of the grain and grain boundary contribution on the polarization process of the material. The analysis of complex modulus spectroscopy exhibits the non-Debye relaxation in the compound. The doping of stannum at the titanium-site of BNT enhances the dielectric characteristics of the material. [ABSTRACT FROM AUTHOR]

Chemical solution deposition was used to deposit epitaxial BaxSr(1−x)TiO3 thin films on SrTiO3 template layers on Si(001) for x = 1.0, 0.7, 0.5, 0.3, and 0.0. Effective Pockels coefficients were determined as a function of film composition both for as‐deposited films (crystallized at 600°C) and for the films after annealing at 750°C for 10 hours. Pockels response decreased monotonically with decreasing Ba content and coefficients were higher for annealed films, reaching 89 ± 3 pm/V for annealed BaTiO3. These results are contextualized with the aid of X‐ray diffraction and high‐resolution transmission microscopy, which illuminated the crystallinity and defect nature of the films. [ABSTRACT FROM AUTHOR]

The present study briefs the structural and optical properties of Gd doped BaZr0.05Ti0.95O3 ceramic synthesized via solid-state reaction (SSR) technique. The X-Ray diffraction (XRD) study reveals the formation of single phase of Gd modified BaZr0.05Ti0.95O3 ceramic. The Fourier transform infrared (FTIR) spectra are also presented in support of structural properties. The optical band-gap obtained from the UV-visible study, decreases with an increase in the Gd content. The photoluminescence study shows a broad hump around 560 nm. The studied compositions reveal the major contribution of shallow holes as compared to deep holes within the band-gap. [ABSTRACT FROM AUTHOR]

Empirically derived predictive models describing synthesis‐structure relationships have the potential to significantly improve and guide future research in a more cost‐effective and timely manner; however, few of these models exist for cation ordering in perovskites. In this study, four compositions within the AZn0.5Ti0.5O3 system (A = Nd, Sm, Nd0.5La0.5, Nd0.5Gd0.5) were synthesized using a conventional solid‐state mixed‐oxide method. X‐ray diffraction data show evidence of long‐range 1:1 rock salt cation ordering on the B site for all compositions. Additional data for other rock salt B‐site ordered compositions were mined from literature. Correlative models for the B‐site shrinkage (ΔrB) have been derived for each B‐site ordered system, and a general model has been developed for rock salt B‐site ordering from these specific models. This general model allows for the prediction of the room‐temperature volume shrinkage resulting from rock salt B‐site ordering using only published ionic radii data. [ABSTRACT FROM AUTHOR]

The Aurivillius-type bismuth layer-structured (NaBi)0.46(LiCe)0.04Bi4Ti4O15 (NBT-LiCe) piezoelectric ceramics were synthesized using conventional solid-state processing. Phase analysis was performed by x-ray diffraction and microstructural morphology was assessed by scanning electron microscopy. The dielectric, piezoelectric, ferroelectric, and electromechanical properties of NBT-LiCe ceramics were investigated. The piezoelectric activities were found to be significantly enhanced compared to NBT ceramics, which can be attributed to the lattice distortion and the presence of bismuth vacancies. The dielectric and electromechanical properties of NBT-LiCe ceramics at elevated temperature were investigated in detail. The excellent piezoelectric, dielectric, and electromechanical properties, coupled with high Curie temperature (Tc=660 °C), demonstrated that the NBT-LiCe ceramics are the promising candidates for high temperature applications. [ABSTRACT FROM AUTHOR]

Stoichiometric and nonstoichiometric (Bi0.5Na0.5)TiO3 (BNT) ceramics were prepared by a conventional ceramic fabrication process. This study revealed that the high conductivity of BNT ceramics is associated with Bi vaporization during sintering. An x-ray study revealed that a tetragonal phase exists in the temperature range between 330 and 480 °C in BNT ceramic as well as BNT single crystals. In addition, the depolarization temperature Td, rhombohedral-tetragonal phase transition temperature TR-T, and the temperature Tm of the maximum dielectric constant were determined to be 187, approximately 300, and 325 °C, respectively, from the temperature dependences of dielectric properties using unpoled and poled specimens. The piezoelectric properties of all vibration modes and the temperature dependences of the piezoelectric properties were measured using fully poled BNT ceramics. It was also revealed that BNT ceramics exhibit three thermal depoling processes at Td, between Td and TR-T, and between TR-T and Tm from the effects of annealing on the field-induced strain, x-ray diffraction patterns, and dielectric constant of poled specimens. [ABSTRACT FROM AUTHOR]

(Ba0.6Sr0.4)TiO3 (BST) thin films were deposited on (100) and (110) oriented LaAlO3 (LAO) single-crystal substrates by radio-frequency magnetron sputtering system, respectively. X-ray diffraction θ-2θ and [uppercase_phi_synonym]-scans results showed that the BST thin films grown on LaAlO3 (100) displayed (h00) preferred orientation, while the films grown on LaAlO3 (110) indicated (110) preferred orientation. Atomic force microscope revealed that BST films grown on LAO (110) had smoother surface and smaller grain size than that BST films grown on LAO (100). Compared with BST films grown on LAO (100), the BST films grown on LAO (110) had higher tunability and better figure of merit. Additionally, the current-voltage (I-V) measurement indicated that the leakage current density of BST films grown on LAO (110) was obviously reduced compared to that of BST films grown on LAO (100). [ABSTRACT FROM AUTHOR]

[Display omitted] • The physicochemical and optical properties of TiO 2 -modified barium gallo-germanate glasses co-doped with Er3+ and Yb3+ were characterized. • The near-IR luminescence at 1.5 μm (Er3+: 4I 13/2 → 4I 15/2) is enhanced significantly in the TiO 2 -GeO 2 -BaO-Ga 2 O 3 system. • Based on the lifetime values, the energy transfer efficiencies were estimated. • The effect of pair Yb3+/Er3+ was verified by the Stark splitting observed for hypersensitive Er3+:4I 15/2 → 2H 11/2 transition. • XRD analysis confirmed the presence of crystalline phases in the highly Yb3+ and Er3+ co-doped titanate-germanate samples with Yb 2 Ti 2 O 7 and Er 2 Ti 2 O 7 phases. This work combines photoluminescence methods, Raman spectroscopy, and X-ray diffraction (XRD) to expand the knowledge of the effects of pair rare earth ions doping on the physicochemical and near-IR properties of glasses. For this purpose, glass systems based on GeO 2 -BaO-Ga 2 O 3 (GBG) and TiO 2 -GeO 2 -BaO-Ga 2 O 3 (TGBG) doped with Er3+ ions (0.1, 0.25, 0.5 mol%) and Yb3+ ions (0.5, 1.25, 2.5 mol%) were synthesized and analyzed. The near-IR luminescence band corresponding to Er3+:4I 13/2 → 4I 15/2 is narrowed for germanate-based glasses (FWHM = 31 nm), whereas in the presence of TiO 2 is more intense and broadened (FWHM = 65 nm). The energy transfer efficiencies between Yb3+ and Er3+ ions in glass samples have been calculated. Notably, the absorption spectra showed the Stark splitting for the band due to the 4I 15/2 → 2H 11/2 hypersensitive transition. Finally, we find the formation of Er 2 Ti 2 O 7 and Yb 2 Ti 2 O 7 crystalline phases in highly doping titanate-germanate samples. The results provide valuable ideas to evaluate the effect of the rare earths doping procedure on properties of designed glasses for near-IR luminescence applications. [ABSTRACT FROM AUTHOR]

• c/a ratio of Pb 0·92 (La 1-y Eu y) 0·08 (Zr 0·52 Ti 0·48)O 3 (PLZT) film rises with Eu doping. • The d 33 value of PLZT film improves with Eu doping (y = 0.5). • The Young's constant of PLZT film lowers with Eu doping (y = 0.5). • Frequency stability of the PLZT film improves up to 1 MHz with Eu doping (y = 0.5). This paper investigates the effect of europium (Eu3+) doping on the crystal structure, dielectric and piezoelectric properties of lead lanthanum zirconate titanate (PLZT) thin film. For the present study, Pb 0·92 (La 1-y Eu y) 0·08 (Zr 0·52 Ti 0·48)O 3 (PLEZT) compositions with various Eu concentrations (y = 0.0, 0.3, 0.5 and 0.7) were prepared on Si/SiO 2 /Ti/Pt substrates by chemical solution deposition technique. The X-ray diffraction and Raman spectroscopy studies revealed the structural distortions in PLZT films with Eu doping. The piezoelectric charge coefficient showed significant enhancement with Eu doping for y = 0.5 composition, with good room temperature frequency stability. This improvement in the piezoelectric characteristics of PLEZT films is the result of stronger intrinsic contributions brought in by bigger c/a ratios and higher extrinsic contributions from non-180° domain wall motions. [ABSTRACT FROM AUTHOR]

A solid-state reaction was used to develop various concentrations (1, 3, 5 wt %) of yttrium oxide (Y 2 O 3)-doped strontium titanate (SrTiO 3) material. Powder X-ray Diffraction (XRD), Fourier Transform Infrared (FT-IR), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray (EDX) analysis were used to study the structural properties and surface structure nature of the prepared compounds. The tuning of magnetic properties, optical band gap values, and PL emission behaviour of the SrTiO 3 doped with increasing concentrations of Y 2 O 3 from the Vibrating Sample Magnetometer (VSM), UV–visible, and Photoluminescence (PL) spectra have been interoperated in the results and discussion section. The CIE 1931 chromaticity diagram was used to determine the colour coordinates of the prepared samples. [Display omitted] • We obtained pure SrTiO 3 and Yttrium doped (1%, 3%, and 5%) SrTiO 3 were prepared by the SSR method. • The observed XRD pattern indicates the synthesized nanocomposite cubic perovskite with a single-phase structure. • HR-SEM, denotes the nanocomposites were naturally clustered, and the grain size increased gradually as the doping proportion increased • In VSM, the doped samples convert the magnetically inert SrTiO 3 into a magnetic substance. From UV – Vis, we concluded that the material's energy gap decreases while increasing the dopant ratio. • The photoluminescence spectra were carried out to find the presence of the emissivity nature of the prepared samples. The chromaticity diagram confirms that the prepared Pure and 5 % Yttrium doped SrTiO 3 nanocomposites are appropriate for producing white and green colours, respectively. [ABSTRACT FROM AUTHOR]

The gallium-modified bismuth ferrite-lead titanate compositions of 0.4Bi(Ga0.4Fe0.6)O3-0.6PbTiO3 (0.4BGF-0.6PT), has been investigated for the potential as a high-field and high-temperature piezoelectric ceramic. The crystalline solutions of 0.4BGF-0.6PT were fabricated by using the solid-state reaction method. X-ray diffraction analysis revealed that 0.4BGF-0.6PT has a tetragonal perovskite structure. The Curie temperature Tc of 0.4BGF-0.6PT was determined to be 540 °C. Our 0.4BGF-0.6PT ceramic specimens could withstand the electric field of >250 kV/cm, reflecting the excellent dielectric breakdown strength. The remanent polarization (Pr) and induced strain ([variant_greek_epsilon]) achieved were 30 μC/cm2 and 0.2%, respectively, revealing the strong ferroelectricity of 0.4BGF-0.6PT. The specimen could be poled into the piezoelectric state under a poling field of 240 kV/cm, giving a weak-field piezoelectric constant d33 of 52 pC/N. [ABSTRACT FROM AUTHOR]

The domain structure of ferroelectric ceramics can be altered by the process of electrical poling. This paper develops quantitative approaches for reflection geometry and spherical harmonic texture analysis, both of which describe these changes at angles parallel to and tilted from the poling axis. The x-ray-diffraction approach uses the relative intensity ratio of ferroelectric poles in poled and unpoled lead zirconate titanate to calculate a domain switching fraction (η) or a multiple of a random distribution, which are shown to be linearly related. An x-ray area detector diffractometer was used for these measurements, although the technique applies to any x-ray reflection geometry. The neutron-diffraction approach employs a Rietveld refinement with a spherical harmonic texture model. Both approaches calculate similar domain textures for two poling fields and the small differences between the approaches can be attributed to surface domain texture. This paper shows that the March–Dollase pole distribution function can inadequately describe domain textures. [ABSTRACT FROM AUTHOR]

The lattice parameters and crystallographic texture in La, Sr-doped soft lead zirconate titanate ceramics were examined using high-energy synchrotron x-ray diffraction. The preferred orientations in poled tetragonal and rhombohedral ceramics near the morphotropic phase boundary, caused by ferroelectric domain switching, were determined by monitoring the (002) / (200) and (111) / (111) intensity ratios, respectively. The lattice strains were also monitored using the {111} and {200} plane spacings in tetragonal and rhombohedral ceramics, respectively. The diffraction experiments were carried out in transmission, enabling the true ‘bulk’ state to be characterized. It was observed that for the tetragonal phase both the lattice spacing d{111} and the intensity ratio R{200} varied linearly as a function of sin² Ψ, Ψ being the angle between the plane normal and the macroscopic polar axis. Similar observations were made for d{200} and R{111} in rhombohedral ceramics. The results are interpreted in terms of the remanent macroscopic strain state due to poling and the resulting relative misfit between any given grain and the surrounding matrix, which creates significant intergranular stresses. The tetragonal {111} and rhombohedral {200} plane spacings were identified as important monitors of intergranular stress, since the elongation of a grain along the tetragonal 〈111〉 or rhombohedral 〈200〉 directions, respectively (due to non-180° domain wall motion), is zero in the absence of the constraint imposed by neighboring grains. As a result, the tetragonal {111} or rhombohedral {200} reflections are sensitive only to the macrostrain of the polycrystal. It is proposed that the nonlinear and hysteretic piezoelectric response of the lattice strain reported in previous studies is primarily a result of coupling between the extrinsic non-180° ferroelectric domain switching mechanisms and the intrinsic lattice strain. [ABSTRACT FROM AUTHOR]

Presents a study which discussed an x-ray diffraction data which showed that from field poling, solid solutions of lead zinc niobate with lead titanate consist of a mixture of a monoclinic and tetragonal phases. Theory of x-ray diffraction; Conclusions.

The structure of rare‐earth titanate melts and glasses of composition 17RE2O3.83TiO2 have been investigated in situ by aerodynamic levitation with laser heating. Ti K‐edge X‐ray absorption near‐edge structure (XANES) spectroscopy reveals an effect of RE cation size on mean Ti‐O coordination numbers (nTiO), which increase from ∼4.8(2) in glass‐forming La titanate to ∼5.1(2) in non‐glass‐forming Sc titanate liquids. We suggest that the associated increase in OTi3 triclusters in melts bearing smaller RE cations tends to inhibit glass formation. Both XANES and high‐energy X‐ray diffraction indicate increases in nTiO as the liquids supercool and vitrify. Results are discussed in the context of alkali and alkaline‐earth titanate glasses, extending the observed dependence of nTiO on structural basicity (modifier content divided by potential) to trivalent modifiers and the molten state. We suggest that the most stable titanate glasses form close to compositions where, on average, two oxygen anions bond to each titanium, allowing a continuous, disordered Ti‐O network of bridging oxygen (OTi2), or with equal numbers of OTi3 triclusters and OTi1 non‐bridging oxygen in charge‐balance. We report on new glasses formed from praseodymium, europium, and gadolinium titanate melts, the latter being the smallest rare‐earth for which binary titanate glasses have been obtained. [ABSTRACT FROM AUTHOR]

Cr-doped PLZT ceramic compositions (Pb 0.94 La 0.06)(Zr 0.57 Ti 0.43)O 3 + X mol% of Cr 2 O 3 , (X = 0.00, 0.05, 0.11 and 0.16) prepared by solid state reaction have been characterized for their structural and pyroelectric properties. Rietveld refinement of X-ray diffraction (XRD) data reveals tetragonal structure with space group P 4 mm , and the tetragonality ratio c / a increases with increasing Cr content. Raman spectroscopy reveals the coexistence of both rhombohedral and tetragonal phases in the system suggesting a polymorphic character providing easy rotation of polarization and improved pyroelectric response. Figures of merit (FOM) useful for device design have been estimated using the measured material properties such as pyroelectric current, density, specific heat, polarization, dielectric constant and loss. A specific Cr 2 O 3 content of X = 0.11 in PLZT is found to exhibit optimum performance characteristics for pyroelectric and thermal energy harvesting applications. [ABSTRACT FROM AUTHOR]

In industry and labs, predictive models describing processing‐structure relationships are inherently valuable, yet few exist for cation ordering in perovskites. In this work, 15 compositions in the [(NayLi1−y)(1−3x)/2La(1+x)/2]TiO3 (NLLT) system (y = 0.25, 0.5, and 0.75; x = 0, 0.0533, 0.1, 0.1733, and 0.225) were synthesized using a conventional solid‐state mixed‐oxide method. X‐ray diffraction data show that some degree of long‐range ordering of A‐site cations exists for x ≥ 0.1, although electron‐diffraction data indicate that short‐range ordering exists even for x < 0.1, with the degree of ordering decreasing as the value of x increases. Empirical models have been derived for the A‐site ordering parameter (η) as well as the resultant expansion (ΔrA) for each y series in the NLLT system, from which two general models were derived for perovskites with any arbitrary degree of 1:1 layered A‐site ordering. These general models allow for the prediction of the order parameter and resulting expansion using only published ionic radii data. A‐site size adjustment factors as functions of composition from experimentally collected data for (NayLi1−y)(1−3x)/2La(1+x)/2TiO3 and A‐site order parameter, η, as a function of composition. The y = 0 data are from Ref. 7. [ABSTRACT FROM AUTHOR]