BaTiO3 Nanocomposites Research Articles

Sr doping effects on La(1-x)SrxMnO3-BaTiO3 nanocomposites: A comprehensive analysis of structural, optical, magnetic, and dielectric properties

Sol-gel synthesized La(1-x)SrxMnO3–BaTiO3 nanocomposites with varying strontium content were investigated to explore the influence of Sr doping on their properties. X-ray diffraction confirmed the perovskite phase purity. Sr doping resulted in a tunable bandgap, widening from 2.33 eV to 2.57 eV as Sr content increased, as revealed by Diffuse Reflectance Spectroscopy. Vibrating Sample Magnetometry measurements exhibited a Sr-dependent decrease in saturation magnetization (22 emu/g for x = 0.2 to 14 emu/g for x = 0.5). Dielectric analysis demonstrated an enhanced dielectric constant and the emergence of new relaxation behaviors with Sr doping. These findings unveil the tailorable optical, magnetic, and dielectric properties of LSMO-BTO nanocomposites due to Sr doping, suggesting their potential for diverse technological applications.

Development, Dielectric Response, and Functionality of ZnTiO3/BaTiO3/Epoxy Resin Hybrid Nanocomposites

In the present work, hybrid nanocomposites of an epoxy resin reinforced with ZnTiO3 and BaTiO3 nanoparticles, at various filler contents, were fabricated and studied. The successful integration of ceramic nanofillers and the fine distribution of nanoparticles were confirmed via X-ray Diffraction patterns and Scanning Electron Microscopy images, respectively. Dielectric properties and related relaxation phenomena were investigated via Broadband Dielectric Spectroscopy in a wide range of frequencies and temperatures. Data analysis showed that dielectric permittivity increases with filler content, although optimum performance does not correspond to the maximum ZnTiO3 content. Four relaxation processes were observed and attributed to interfacial polarization (IP) (at low frequencies and high temperatures), glass-to-rubber transition (α-relaxation) of the epoxy matrix (at intermediate frequencies and temperatures), and local rearrangements of polar side groups of the macromolecules (β-relaxation) and small flexible groups of the main polymer chain (γ-relaxation) occurring at low temperatures and high frequencies. The ability of hybrid nanocomposites to store and retrieve energy was studied under dc conditions by employing a charging/discharging sequence. The stored and retrieved energy increases with filler content and charging voltage. The optimum ability of energy recovering, shown by the epoxy/7 phr ZnTiO3/7 phr BaTiO3 nanocomposite, ranges between 30 and 50 times more than the matrix, depending on the time instant. The employed nanoparticles induce piezoelectric properties in the nanocomposites, as found by the increase in the piezoelectric coefficient with filler content.

Multifunctional Phra Phrom‐like Graphene‐Based Membrane for Environmental Remediation and Resources Regeneration

AbstractWater and energy shortages are interdependent major worldwide issues that cannot be disregarded. In this work, graphene and BaTiO3 are used to synergistically facilitate the self‐assembly of the β‐phase that is known to induce the piezoelectric properties of the polyvinylidene fluoride (PVDF). This leads to a PVDF/graphene‐BaTiO3 nanocomposite with a unique capability of integrating Phra Phrom‐like four functions into one single asymmetric membrane: i) solar evaporation, ii) power generation, iii) piezo‐photodegradation, and iv) self‐cleaning/monitoring for environmental remediation and resources regeneration. The high heat accumulation capability and piezoelectric performance of the membrane enable it to simultaneously achieve a water production rate of 0.99 kgm−2h−1, in compliance with WHO standards, and a maximum power output of 5.73 Wm−2 in simulated natural environments. Upon subjecting the membranes to environmental cleaning, they not only show a 93% dye degradation rate due to the synergistic effect of piezoelectricity and photocatalysis but also resolve the membrane fouling issue, exhibiting ≈200% resistance change compared to the static state. The successful integration of these four functions into one membrane shows the great potential of this work toward a more sustainable and viable water and energy production approach.

Facile synthesis of a GO-g-C3N4/BaTiO3 ternary nanocomposites for visible-light-driven photocatalytic degradation of rhodamine B

Photogenerated charge carriers can undergo rapid recombination in conventional photocatalyst systems, reducing their photocatalytic efficiency. To address this bottleneck, a g-C3N4/BaTiO3 (CNB) heterojunction composite was decorated with different mass ratios of graphene oxide (GO) to form a novel visible-light responsive ternary GO-g-C3N4/BaTiO3 (GOCNB) nanocomposite using a facile fabrication method. The GOCNB photocatalyst exhibited significantly higher light absorption and greater charge transfer than CNB, g-C3N4, or BaTiO3. The photodegradation performance of GOCNB was optimized with a 2% mass loading of GO, and it achieved a degradation rate constant of 14.9 × 10−3 min−1 for rhodamine B with an efficiency of 94% within 180 min. The rate constant was 8-fold and 6-fold higher than that of bare BaTiO3 and CNB, respectively. The stronger photocatalytic activity was attributed to the synergistic effect of GO, g-C3N4, and BaTiO3, with g-C3N4 and BaTiO3 promoting charge transfer within a wider visible light range and GO promoting electron mobility and the photocatalyst's adsorption capacity. In particular, the proposed system maintained the spatial separation of photogenerated electron–hole pairs, which is vital for high photocatalytic activity. This study provides new insights into semiconductor-based photocatalytic systems and suggests a route for more environmentally sustainable technologies.

Synthesis of BaTiO3/Ag nanocomposites using a sonochemical process and low-temperature sintering

ABSTRACT A barium titanium oxide/silver (BaTiO3/Ag) nanocomposite powder was synthesized using a sonochemical process. By irradiating an ethanol solution of BaTiO3 and silver oxide (Ag2O), Ag2O thermally decomposed at 40°C and Ag-loaded BaTiO3 nanocomposites powder was obtained. Nanocomposites containing 30 vol% Ag sintered at 1000°C showed near densities and higher dielectric constants compared to those of BaTiO3 sintered at 1300°C. Moreover, percolation did not occur because the Ag nanoparticles were uniformly dispersed and loaded onto the surface of BaTiO3. This sonochemical method is expected to be a new process for obtaining uniformly dispersed and loaded nanocomposite powders without percolation, even in large amounts.

CoFe2O4 -BaTiO3 nanocomposites; role of ferrite phase on the structural, optical and magnetic properties

The structural, optical, and magnetic characteristics of the (CoFe2O4) x – (BaTiO3)100-x (x = 10, 20, 30, 40, 50) nanocomposites prepared using the sol-gel technique were examined. X-ray diffraction data confirm formation of the tetragonal phase for BTO and the spinel phase for CFO for all composites. The magnetic hysteresis loop measurements were performed using a vibrating sample magnetometer at room temperature. All of the composites had improved ferromagnetic characteristics, which are highly influenced by the amount of the CFO phase. The bandgap energy values decreased as the CFO concentration increased. The dielectric constant, loss function and conductivity for samples were measured.

A study on structural, optical, and magnetic properties of MgFe2O4–BaTiO3 nanocomposites

A study on structural, optical, and magnetic properties of MgFe2O4–BaTiO3 nanocomposites

Room temperature multiferroic behavior of CoFe2O4–BaTiO3 nanocomposites prepared by the co-precipitation method

Room temperature multiferroic behavior of CoFe2O4–BaTiO3 nanocomposites prepared by the co-precipitation method

Nanomechanical and thermomechanical evaluation of polypropylene nanocomposites containing functionalized boron nitride decorated with barium titanate

ABSTRACT This study developed polypropylene (PP) nanocomposites containing surface-functionalized boron nitride (BN) decorated with BaTiO3 (BT). The developed nanocomposites showed well-dispersed nanoparticles in the PP matrix. The nanocomposites showed optimal hardness, elastic modulus, and stiffness of about 166.6 MPa, 2.7 GPa, and 0.12 mN/nm for PP/15BN-5BT nanocomposite compared to 79.4 MPa, 1.7 GPa, and 0.089 mN/nm measured for the pure PP, which are increments of about 110%, 59%, and 35% respectively. Heat deflection temperature and dynamic mechanical properties were also enhanced. Therefore, this study discussed the effects of BN decorated with BT on the nanomechanical and thermomechanical properties of PP nanocomposites.

Concurrently enhanced dielectric properties and energy density in poly(vinylidene fluoride)-based core–shell BaTiO3 nanocomposites via constructing a polar and rigid polymer interfacial layer

Two interfacial modifiers were designed to investigate the influence of their chain conformation and band-gap width on the dielectric behavior and energy storage properties of poly(vinylidene fluoride)-based BaTiO3 nanocomposites.

Thermal, mechanical and dielectric properties of functionalized sandwich BN-BaTiO3-BN/polypropylene nanocomposites

Research attention has been drawn towards the development of polypropylene (PP) based materials, which simultaneously have large dielectric constant, mechanical strength, and thermal stability for power-related applications. This study achieved that by using sandwich structured BN-BaTiO3-BN in modification of PP matrix. The BN-BaTiO3-BN sandwich nanoparticles were prepared via hydrothermal and assembly techniques. Before that, the nanoparticles were surface functionalized using 3-glycidoxypropyltrimethoxysilane. The functionalized nanoparticles were investigated using FTIR and TGA, which confirmed successful functionalization. Molten polypropylene grafted maleic anhydride (PPMA) compatibilizer was used to wrap the BN and BaTiO3 (BT) nanoparticles, which also promoted their compatibility with the PP matrix. The nanocomposites were prepared via melt compounding method using rheomixer. The developed PP nanocomposites showed enhanced DSC properties and thermal stability (above 20 °C compared to the pure PP). In addition, the dielectric constant increased from 2.02 at 100 Hz for the pure PP to 4.68 for PP/5BN-15BT nanocomposite, which is about 132% increase. The nanocomposite also retained an appreciable low loss of about 0.05 at 100 Hz. The enhanced dielectric and thermal properties are required for optimal performance of PP dielectric film capacitor for power applications and miniaturization of electronic components. The various improved properties were attributed to interfacial polarization, interlocking of PP chains and thermal barriers in the PP matrix offered by the nanoparticles.

Changes in the dielectric constant of interphase volume in polyimide–ceramic nanocomposites: A power law model approach

AbstractThe interphase properties in nanocomposites indicate the interaction between filler and matrix, which is dependent on the preparation method, shape, and size of filler and the chemical interaction between two phases. Local chemical environment in polymer matrix give rise to the different dielectric properties compared to that of bulk material. These properties allow the understanding of their effects on the dielectric properties and glass transition (Tg) of the nanocomposites. In this study, interphase power law model was used to predict the interphase properties based on the experimental dielectric constant of polyimide (PI) with BaTiO3, TiO2, and ZrO2 nanocomposites. They were prepared via in situ polymerization of PI whose dielectric constant were increased at interphase filler volume fraction of BaTiO3, TiO2, and ZrO2 at 3.8, 2.05, and 1.7, respectively. These results indicate that PI/ceramics nanocomposites had poor dispersion and weak interphase interaction between the filler and the matrix, as an evidence of scanning electron microscopy and Fourier transform infrared spectroscopy results. However, PI incorporated with high aspect ratio of BaTiO3 nanofiber shows better dispersion than nanocomposites of TiO2 and ZrO2 filled PI; therefore provide higher dielectric constant and Tg.

Effect of BaTiO3 phase on frequency dispersion characteristics of Mg0.48Cu0.12Zn0.4Fe2O4 + BaTiO3 nanocomposites

Multiferroic nanocomposites of ferrite and ferroelectric phases with systematically varying composition (100-x)Mg0.48Cu0.12Zn0.4Fe2O4 + xBaTiO3 (MCZBT) (where, x = 0, 20, 40, 50, 60, 80, 100 mol%) were prepared for the first time by mechanical milling and sintering method. The presence of ferrite and ferroelectric phases in nanocomposite samples were confirmed by X-ray diffraction (XRD) while microstructural characterization was carried out by scanning electron microscopy (SEM). The average grain size, from SEM, was found to be in the range 80 nm for ferrite and 86 nm for BaTiO3 nanopowders. The complex permittivity and the complex permeability variations as a function of frequency in the range 100 kHz – 1.8 GHz, were investigated using LCR meter and Impedance analyzer. The resonance and relaxation phenomena were observed by all the samples around 1.18 GHz from the permittivity studies. From the studies of microwave absorbing properties in X-band (8–12 GHz) frequency region, it was found that the minimum reflection loss of −24.61 dB with bandwidth of 0.38 GHz was obtained by sample with 20% ferroelectric phase. The studies on reflection loss and transmission loss indicated that the effective absorption of incident microwave was found to be above 80% and the composite sample with 80% of ferroelectric phase absorbed more than 91% of the incident wave. The results suggested that the present sample materials can be used for making microwave shielding devises for EMI applications.

High‐performance P(VDF‐TrFE)/BaTiO3 nanocomposite based ferroelectric field effect transistor (FeFET) for memory and switching applications

AbstractThe ferroelectric field effect transistor (FeFET) using Poly (vinylidene fluoride‐trifluoroethylene)/Barium titanate [P(VDF‐TrFE)/BaTiO3] polymer nanocomposite as dielectric layer, has been fabricated and characterized. P(VDF‐TrFE)/BaTiO3 nanocomposite of 300 nm thin film over 10 nm SiO2 was used in the optimized fabrication process sequence of FeFET. The addition of BaTiO3 nanoparticle to the P(VDF‐TrFE) copolymer has enhanced the ferroelectric property with an observed 2 V difference in memory window. The effect of temperature and frequency on these memory window characteristics were observed to optimized the stack thickness for an ideal FeCAP (ferroelectric capacitor). Drain current–drain voltage (ID‐VD) characteristics of P(VDF‐TrFE)/BaTiO3 FeFET shows significant variation in ID with pinch of voltage around 1 V for wide range of gate voltage (VG). ION/IOFF ratio of FeFET using P(VDF‐TrFE)/BaTiO3 was found to be 35, which was higher than the ratio of FeFET fabricated using P(VDF‐TrFE) copolymer (4.4). ID‐VG characteristics of both the FETs clearly indicate a lower threshold voltage (0.83 V) for P(VDF‐TrFE)/BaTiO3 FET, which is almost three times lesser than threshold voltage of a P(VDF‐TrFE) FET (2.5 V).

Comparative studies of silane coupled e‐glass fiber and e‐glass fiber reinforced bismaleimide‐epoxy hydroxylated BaTiO3 nanocomposites on the dielectric and mechanical properties

AbstractSilane coupled E‐glass fiber (SC‐EGF) and E‐glass fiber (EGF) reinforced bismaleimide (BMI)‐epoxy‐hydroxylated BaTiO3 (BTOH) nanocomposites with 1–5 wt% of BTOH nanofiller were fabricated by hand lay‐up method and compression molded. Surface hydroxylation of synthesized BaTiO3 nanoparticles was carried out using H2O2. Both BT and BTOH nanoparticles were characterized by SEM, XRD, and FTIR studies. Among the reinforced nanocomposites, SC‐EGF‐reinforced showed a remarkable increase in mechanical and dielectric properties. The tensile strength of BMI‐epoxy composite increased 1.56 and 3.10 times when loaded with 2 and 3 wt% of BTOH, respectively. Their flexural strength too increased 2.14 and 2.21 times upon 2 and 3 wt% of BTOH loading. BMI‐epoxy‐BTOH nanocomposites with 3 wt% of BTOH showed higher tensile strength, flexural strength, and dielectric strength indicating that it possesses better mechanical and insulating properties and composites with 2 wt% showed higher dielectric constant and lower dielectric loss indicating that this composition could be explored to high dielectric applications.

Synthesis of BaTiO3-CoFe2O4 nanocomposites using a one-pot technique

Low-cost and scalable sol–gel chemistry was employed to obtain ferroelectric-ferrimagnetic BaTiO3-CoFe2O4 nanocomposites. In a novel one-pot synthesis method, both the constituent phases of nanocomposites are formed during the same time and symbiotically participate to each other’s growth. X-ray powder diffraction evidences the phase purity of the systems, with average crystallite sizes in the order of 20 nm for the BaTiO3 phase. The optimization of the synthesis conditions, precursors, and chemical agents for nanoscale BaTiO3 and BaTiO3-CoFe2O4 nanocomposites is presented, together with the magnetic and/or dielectric properties of the obtained materials. BaTiO3-CoFe2O4 nanocomposites with up to 20% CoFe2O4 volume fractions were found to display ferrimagnetic properties at room temperature akin to those of CoFe2O4, while preserving a dielectric behavior reminiscent of BaTiO3. Preliminary results describing the spin coating of BaTiO3 and BaTiO3-CoFe2O4 nanocomposites as thin films are also reported.

Improved Dielectric Properties of Polypropylene Nanocomposites with BaTiO3 Nanoparticles

Polymer nanocomposites with improved dielectric permittivity are extremely desirable for the power capacitors. With the existing capacitor polypropylene (PP) film as the substrate, the surface of PP film is coated with a layer of BaTiO3 (BT) with high dielectric constant of nanoparticles. Through the BT layer with high dielectric constant, the dielectric constant of the whole composite dielectric film is improved, and the dielectric loss is controlled at a relatively low level. The organic solvent system of BT paste coating and water system of BT paste coating research were prepared. Two kind of composite dielectric films which are PP/PVDF/BT and PP/BT were prepared by coating. The permittivity of PP/ BT nano-composites with 50 wt% fillers at 1000 Hz was up to 4.49, which was nearly 2 times higher than that of pure PP film. According to the method, a pilot experiment was carried out. The strategy could be extended to a variety of inorganic fillers to improve the dielectric properties of polymer nano- composites for power capacitors.

High permittivity BaTiO3 and BaTiO3-polymer nanocomposites enabled by cold sintering with a new transient chemistry: Ba(OH)2∙8H2O

Cold sintering process (CSP) offers a promising strategy for the fabrication of innovative and advanced high permittivity dielectric nanocomposite materials. Here, we introduce Ba(OH)2∙8H2O hydrated flux as a new transient chemistry that enables the densification of BaTiO3 in a single step at a temperature as low as 150 °C. This remarkably low temperature is near its Curie transition of 125 °C, associated with a displacive phase transition. The cold sintered BaTiO3 shows a relative density of 95 % and a room temperature relative permittivity over 1000. This new hydrated flux permits the fabrication of a unique dense BaTiO3-polymer nanocomposite with a high volume fraction of ceramics ((1-x) BaTiO3 – x PTFE, with x = 0.05). The composite exhibits a relative permittivity of approximately 800, at least an order of magnitude higher than previous reports on polymer composites with BaTiO3 nanoparticle fillers that are typically well below 100. Unique high permittivity dielectric nanocomposites with enhanced resistivities can now be designed using polymers to engineer grain boundaries and CSP as a processing method opening up new possibilities in dielectric materials design.

High-throughput data-driven interface design of high-energy-density polymer nanocomposites

Understanding the interface effect in dielectric nanocomposites is crucial to the enhancement of their performance. In this work, a data-driven interface design strategy based on high-throughput phase-field simulations is developed to study the interface effect and then optimize the permittivity and breakdown strength of nanocomposites. Here, we use two microscopic features that are closely related to the macroscopic dielectric properties, the thickness and permittivity of the interface phases, to evaluate the role of interfaces in experimental configuration, and thus provide quantitative design schemes for the interfacial phases. Taking the polyvinyl difluoride (PVDF)BaTiO3 nanocomposite as an example, the calculation results demonstrate that the interfacial polarization could account for up to 83.6% of the increase in the experimentally measured effective permittivity of the nanocomposite. Based on the interface optimized strategy, a maximum enhancement of ∼156% in the energy density could be achieved by introducing an interface phase with d/r = 0.55 and εinterface/εfiller=0.036, compared to the pristine nanocomposite. Overall, the present work not only provides fundamental understanding of the interface effect in dielectric nanocomposites, but also establishes a powerful data-driven interface design framework for such materials that could also be easily generalized and applied to study interface issues in other functional nanocomposites, such as solid electrolytes and thermoelectrics.

Glass fiber reinforced bismaleimide/epoxy BaTiO3 nano composites for high voltage applications

BaTiO3/bismaleimide/epoxy/glass fiber reinforced composites were prepared using E-glass fiber (E-GF) and silane coated E-glass fiber (SC-EGF) separately as reinforcement. BaTiO3 nanoparticles were prepared by hydrothermal method. Results show that the addition of BaTiO3 nanoparticles has significant effects on the mechanical and dielectric properties of the composite. Both E-GF and SC-EGF reinforced BaTiO3/bismaleimide/epoxy composites with 2 wt percentages of BaTiO3 nanoparticles showed improved tensile strength, flexural strength and dielectric constant and those with 3% showed high dielectric strength indicating this composition is more adaptable for high voltage insulating applications. Dielectric constants and dielectric loss of the fabricated nanocomposites have been obtained at higher frequencies (in GHz) by using Vector Network Analyser at room temperature and was found to be highest for the BMI-Epoxy nanocomposite with 1% weight nanofiller.