scholarly journals Structural, Magnetic, Dielectric and Energy Storage Analysis of CoFe2O4@BaTiO3 and BaTiO3@CoFe2O4 Core-Shell Nano- Composites

2020 ◽  
Author(s):  
NIDHI SHEORAN ◽  
Vinod Kumar ◽  
Ashok Kumar
Keyword(s):  
Energy Storage ◽  
Spinel Ferrite ◽  
Sol Gel ◽  
Maximum Energy ◽  
Tangent Loss ◽  
Core Shell ◽  
Loop Analysis ◽  
Energy Storage Properties ◽  
Energy Storage Efficiency ◽  
Co Precipitation

Abstract Nano size spinel ferrite CoFe2O4 (CFO), ferroelectric BaTiO3 (BTO) and their core-shell nanocomposites BTO@CFO and CFO@BTO were synthesized using combination of chemical co-precipitation and sol-gel route respectively. The phase formation and crystallinity of bare CFO, BTO and their core-shell nanocomposites were verifiedviaX-ray diffraction pattern (XRD). High resolution transmission electron microscopy(HRTEM) revealed the core-shell structure of the nanocomposites.Magnetization measurements exhibitferromagnetic behaviour of all the samples except BTO in which superposition of weak ferromagnetic and diamagnetic response occurred due to its nanostructure. Magnetization versus temperature (M-T plot) measurements show anomaly near ferroelectric to paraelectric phase transition of BTO. Also,dielectric constant(ε¢) and tangent loss (tanδ) variation with respect to frequency (102 to 106 Hz) and temperature (300-700 K) were presented. ε¢-T curve of nanocomposites exhibit anomaly at the same temperature as observed in M-T plot of nanocomposites that indicate the inherent magneto-electric coupling in nanocomposites. Energy storage properties of BTO and nanocomposites have been examined via P-E loop analysis and confirmed that the sample CFO@BTO exhibit maximum energy storage efficiency.

scholarly journals Temperature-dependent energy storage characterization of Pb-free relaxor ferroelectrics

2020 ◽  
Vol 10 (03) ◽  
pp. 2050009
Author(s):  
Sarir Uddin ◽  
Guang-Ping Zheng ◽  
Asif Khan ◽  
Muhammad Riaz Khan ◽  
Banaras Khan
Keyword(s):  
Energy Storage ◽  
Electric Field ◽  
Sol Gel ◽  
Relaxor Ferroelectrics ◽  
Maximum Energy ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
Increase With Increase ◽  
Energy Storage Properties ◽  
Increasing Temperature

The energy storage properties of [Formula: see text][Formula: see text][Formula: see text]TiO3–[Formula: see text]BaTiO3([Formula: see text]) (BNT–BT) ceramics obtained via sol–gel method are determined from the polarization versus electric field ([Formula: see text]–[Formula: see text]) loops at various temperatures. The energy storage densities are observed to increase with increase in temperature and this may be attributed to the presence of antiferroelectric (AFE) phase at higher temperature ([Formula: see text]C). Obvious changes are observed in the saturation polarization ([Formula: see text] and remnant polarization ([Formula: see text] with increasing temperature. The maximum energy storage density of 0.6[Formula: see text]J/cm3 is observed for [Formula: see text] in the AFE phase at 150∘C for 90[Formula: see text]kV/cm of applied electric field. BNT–BT can be a promising candidate for energy storage devices to be used in above-room-temperature environment.

scholarly journals Construction of a Three-Dimensional BaTiO3 Network for Enhanced Permittivity and Energy Storage of PVDF Composites

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3585
Author(s):  
Xueqing Bi ◽  
Lujia Yang ◽  
Zhen Wang ◽  
Yanhu Zhan ◽  
Shuangshuang Wang ◽  
...  
Keyword(s):  
Energy Storage ◽  
Polyvinylidene Fluoride ◽  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Sol Gel ◽  
Three Dimensional ◽  
Low Dielectric ◽  
Energy Storage Properties ◽  
Discharge Energy Density ◽  
Pure Pvdf

Three-dimensional BaTiO3 (3D BT)/polyvinylidene fluoride (PVDF) composite dielectrics were fabricated by inversely introducing PVDF solution into a continuous 3D BT network, which was simply constructed via the sol-gel method using a cleanroom wiper as a template. The effect of the 3D BT microstructure and content on the dielectric and energy storage properties of the composites were explored. The results showed that 3D BT with a well-connected continuous network and moderate grain sizes could be easily obtained by calcining a barium source containing a wiper template at 1100 °C for 3 h. The as-fabricated 3D BT/PVDF composites with 21.1 wt% content of 3D BT (3DBT–2) exhibited the best comprehensive dielectric and energy storage performances. An enhanced dielectric constant of 25.3 at 100 Hz, which was 2.8 times higher than that of pure PVDF and 1.4 times superior to the conventional nano–BT/PVDF 25 wt% system, was achieved in addition with a low dielectric loss of 0.057 and a moderate dielectric breakdown strength of 73.8 kV·mm−1. In addition, the composite of 3DBT–2 exhibited the highest discharge energy density of 1.6 × 10−3 J·cm−3 under 3 kV·mm−1, which was nearly 4.5 times higher than that of neat PVDF.

Extraordinary energy storage performance and thermal stability in sodium niobate-based ceramics modified by the ion disorder and stabilized antiferroelectric orthorhombic R phase

2021 ◽  
Author(s):  
Ruirui Kang ◽  
Zepeng Wang ◽  
Weijie Yang ◽  
Xiaopei Zhu ◽  
Peng Shi ◽  
...  
Keyword(s):  
Energy Storage ◽  
Electric Vehicles ◽  
High Performance ◽  
Hybrid Electric Vehicles ◽  
Sodium Niobate ◽  
Storage Efficiency ◽  
Storage Performance ◽  
Energy Storage Properties ◽  
Energy Storage Efficiency ◽  
Storage Properties

Developing high-performance dielectric capacitors is essential to meet the growing demands of hybrid electric vehicles and high-power applications. The energy storage efficiency and the temperature-variant energy storage properties should be...

scholarly journals Magnetite-Silica Core/Shell Nanostructures: From Surface Functionalization towards Biomedical Applications—A Review

2021 ◽  
Vol 11 (22) ◽  
pp. 11075
Author(s):  
Angela Spoială ◽  
Cornelia-Ioana Ilie ◽  
Luminița Narcisa Crăciun ◽  
Denisa Ficai ◽  
Anton Ficai ◽  
...  
Keyword(s):  
Magnetite Nanoparticles ◽  
Biomedical Applications ◽  
Sol Gel ◽  
Magnetic Nanomaterials ◽  
Core Shell ◽  
Synthesis Methods ◽  
Shell Nanostructures ◽  
Silica Core ◽  
Magnetic Resonance Imaging Mri ◽  
Co Precipitation

The interconnection of nanotechnology and medicine could lead to improved materials, offering a better quality of life and new opportunities for biomedical applications, moving from research to clinical applications. Magnetite nanoparticles are interesting magnetic nanomaterials because of the property-depending methods chosen for their synthesis. Magnetite nanoparticles can be coated with various materials, resulting in “core/shell” magnetic structures with tunable properties. To synthesize promising materials with promising implications for biomedical applications, the researchers functionalized magnetite nanoparticles with silica and, thanks to the presence of silanol groups, the functionality, biocompatibility, and hydrophilicity were improved. This review highlights the most important synthesis methods for silica-coated with magnetite nanoparticles. From the presented methods, the most used was the Stöber method; there are also other syntheses presented in the review, such as co-precipitation, sol-gel, thermal decomposition, and the hydrothermal method. The second part of the review presents the main applications of magnetite-silica core/shell nanostructures. Magnetite-silica core/shell nanostructures have promising biomedical applications in magnetic resonance imaging (MRI) as a contrast agent, hyperthermia, drug delivery systems, and selective cancer therapy but also in developing magnetic micro devices.

scholarly journals Effect of sintering temperature on the dielectric, ferroelectric and energy storage properties of SnO2-doped Bi0.5(Na0.8K0.2)0.5TiO3 lead-free ceramics

2020 ◽  
Vol 10 (04) ◽  
pp. 2050011
Author(s):  
Nguyen Truong-Tho ◽  
Le Dai Vuong
Keyword(s):  
Dielectric Constant ◽  
Energy Storage ◽  
Sintering Temperature ◽  
High Energy ◽  
Lead Free ◽  
Energy Storage Properties ◽  
Energy Storage Efficiency ◽  
High Dielectric ◽  
Storage Properties ◽  
High Energy Storage

Sintered lead-free [Formula: see text]([Formula: see text][Formula: see text]([Formula: see text][Formula: see text]O3 ceramics (BNKTS) have been fabricated via a solid-state reaction. The effect of sintering temperature on the structural, morphological, dielectric, ferroelectric and energy storage properties of BNKTS ceramics was investigated, and it was found that the electrical properties of the synthesized ceramics increased with the increase in the sintering temperature, and the highest values were achieved at [Formula: see text]C. The ceramics sintered at the optimized temperature of [Formula: see text]C exhibited the best physical, dielectric, ferroelectric and energy storage properties, namely, high density (the relative density, [Formula: see text][Formula: see text]g.cm[Formula: see text], approximate to 96.7% of the theoretical value), high densification factor ([Formula: see text]), high dielectric constant ([Formula: see text]), low dielectric loss (tan[Formula: see text]), highest dielectric constant ([Formula: see text]), high remanent polarization ([Formula: see text]C.cm[Formula: see text], high coercive field ([Formula: see text][Formula: see text]kV/cm), high energy storage density (0.12[Formula: see text]J/cm[Formula: see text], and high energy storage efficiency (41.7% at 46.3[Formula: see text]kV/cm).

Preparation, Characterization and Visible-Light Catalytic Activity of Core-Shell Structure NiFe2O4@TiO2 Ferrite Nanoparticles

2016 ◽  
Vol 680 ◽  
pp. 272-277
Author(s):  
Zhou Li Lu ◽  
Peng Zhao Gao ◽  
Rui Xue Ma ◽  
Yu Kun Sun ◽  
Dong Yun Li
Keyword(s):  
Catalytic Activity ◽  
Visible Light ◽  
Shell Structure ◽  
Shell Thickness ◽  
Spinel Ferrite ◽  
Sol Gel ◽  
Magnetic Core ◽  
Core Shell ◽  
Calcination Temperatures ◽  
Core Shell Structure

The core-shell structure NiFe2O4@TiO2 nanoparticles was successfully prepared using a sol-gel method, the influence of shell thickness and calcination temperatures on the composition, microstructure, magnetic properties and visible-light catalytic activity of the nanoparticles was studied by XRD, TEM, Uv–vis, vibrating sample magnetometer, etc. Results showed the main composition of core in NiFe2O4@TiO2 was spinel ferrite, and the shell was anatase TiO2, and theshell thickness increased significantly with the increase of TiO2 content, ranging from 10nm to 50nm. The Ms and Mr of nanoparticles decreased with the increase of TiO2 content, and no obvious reaction between the magnetic core and shell occurred; visible-light degradation percent of NiFe2O4@TiO2 nanoparticles increased along with the increase of TiO2 content, whereas the recovery rate of it decreased. Degradation percent and the recovery percent of NiFe2O4@TiO2-50 still reached 93.7% and 90.5%, even after 10 cycle times, respectively, possessing the excellent long-term stability.

Preparation and Magnetic Properties of Monodisperse Nanocomposite Hollow Spheres

2007 ◽  
Vol 998 ◽  
Author(s):  
Chun-Rong Lin ◽  
Cheng-Chien Wang ◽  
I-Han Chen
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Saturation Magnetization ◽  
Magnetic Measurements ◽  
Spinel Ferrite ◽  
Sol Gel ◽  
Hollow Spheres ◽  
Core Shell ◽  
Ferromagnetic Behavior ◽  
Mixed Gas

ABSTRACTWe present a simple process to prepare the hollow ceramic (CoFe2O4/SiO2) composite nanospheres and hollow alloy (Co33Fe67/SiO2) composite nanospheres. The hollow CoFe2O4/SiO2 composite nanospheres were prepared by calcining polymer/CoFe2O4/SiO2 core/shell composite spheres which were synthesized by the sol-gel method following the chemical co-precipitation. In a typical process, the monodisperse polymer poly(MMA-co-MAA) latex (450 nm) was used as a core template. To create hollow CoFe2O4/SiO2 spherical structures with various sizes of CoFe2O4 nanoparticles, the hybrid PMMA/CoFe2O4/SiO2 core-shell spheres were subsequently calcined in the temperature range from 450 to 900°C for 4h. On the other hand, the hollow Co33Fe67/SiO2 composite nanospheres were formed by reduction of hollow CoFe2O4/SiO2 nanospheres in a stream of H2/Ar mixed gas at 900°C for 8 hrs. X-ray diffraction pattern shows that the coated phase of the hollow CoFe2O4/SiO2 composite nanospheres has a cubic spinel ferrite structure. Based on the thermogravimetric analysis (TGA), we found that the content of CoFe2O4 is 73 wt% in the hollow CoFe2O4/SiO2 composite shell. The scanning electron microscope and transmission electron microscope photographs show that the hollow spheres are uniform. According to the line scanning EDX analysis of the cross section of hollow spheres, the SiO2 is not only coated on the surface of sphere but also distributed over the shell of hollow sphere. The thickness of shell of hollow spheres is about 40 nm. Magnetic measurements show that the saturation magnetization is clearly decreases as the magnetic particle size decreased. This phenomenon can be interpreted as the effect of surface spin canting when the particle size is reduced. As for the hollow alloy (Co33Fe67/SiO2) composite nanospheres, the magnetic phase has a body-centered cubic structure and an average crystallite size of 28.7 nm. This alloy nanospheres exhibit a ferromagnetic behavior with saturation magnetization of 170 emu/g, coercivity of 250 Oe, and Curie temperature of 968 °C. Due to metallic and ferromagnetic behavior of Co33Fe67 nanoparticles, these hollow spheres can be used as a lightweight electromagnetic wave absorber.

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