•The conventional solid state route technique has been adopted for the preparation.•Structural and microstructural investigation reveals formation of the sample.•UV–Visible syudy revels the material ...may be useful for photocatalytic activity.•Dielectric and related measurements infers it can be useful for multi-storage device.
The Sr-modified vanadium-based double perovskite Ba1.5Sr0.5FeVO6 was synthesized by conventional solid solution casting procedure at an optimized temperature 1225 °C. The preliminary structural investigation was carried out through X-ray diffraction (XRD) and scanning electron microscope (SEM). Fourier transforms infrared (FTIR) technique was utilized to distinguish among the different modes of vibration of the elements in the compound. The band gap (2.76 eV) of the material was evaluated through the UV–Visible spectroscopy technique. Dielectric and related measurements were conducted through LCR meter in the frequency range (100 Hz–5 MHz) under the temperature range (25 °C-–500 °C). Room temperature dielectric constant (εr ~ 500) and tangent loss (tanδ ~ 0.08) at 10 kHz suggests material may be useful for multilayer capacitor and other storage devices. Non-destructive impedance spectroscopy (IS) techniques have been adopted for electrical characterization. In addition to the IS further electrical features have been investigated through ac and dc conductivity spectra . For magnetic behavior of the material (M-H) hysteresis was carried out at room temperature to investigate the magnetic properties of the material.
This paper reports the synthesis of Ba
0.92
Ca
0.08
Fe
0.5
Nb
0.5
O
3
ceramics and its structural, dielectric, and electrical characteristics. Preliminary structural analysis through X-ray ...diffraction suggests the single-phase monoclinic crystal symmetry of the sample. Its quality is asserted by microstructural and elemental studies carried out by scanning electron microscopy and energy-dispersive X-ray spectroscopy techniques, respectively. Detailed examination of dielectric and electrical parameters in wide temperature (15–300 °C) and frequency (100–500 kHz) ranges reveals many interesting results that correlate structure with observed characteristics. The complex impedance plots confer the temperature-reliant nature of grain and grain boundary effect.
In this communication, we have opted for modification in BFO owing to its disadvantageous dielectric and high tangent loss by MgTiO
3
, in the form of the derived composite (BiFeO
3
)
0.80
(MgTiO
3
)
...0.20,
bringing in enhancement in the magnetic, dielectric, optical, Impedance, magnetic behavior. The structural investigation was carried out to delineate the lattice formation, space groups, etc. A structural transition from spin cycloid rhombohedral phase to orthorhombic phase was noticed due to the doping by alkaline earth ion-based MgTiO
3
structure. The X-ray photoelectron spectroscopy (XPS) proved the existence of multiple valence states in the ceramic which in turn validates the phenomena of hopping conduction and short-range double-exchange interactions. The Fourier Transform Infrared spectroscopy (FTIR) and Raman analysis give an insight into the various vibrational states that are present in the sample. The modification of BFO reduced the optical bandgap to 2.00 eV from 2.2 to 2.5 eV for pure BiFeO
3
, as divulged from the tauc plot of the absorbance curve. The value of the dielectric permittivity at ambient temperature and low frequency is also significantly high. The impedance and modulus analysis divulge the negative resistance in the studied sample, which enables it to be applied for semiconducting device fabrication. The short-range double exchange interactions between the short-range cluster such as Fe
2+
–V
0
–Fe
3+
induce ferromagnetism in the compound.
An inter hexagonal species structural phase transformation from R3c to R3cH was found while doping BFO with 20% concentration of (CaTiO
3
), which manifests itself as distorted trigonal symmetry. The ...XPS analysis reveals dual oxidation states (Fe
2+
& Fe
3+
) of the Fe2p
3/2
state when deconvoluted. The existence of dominating O
ads
is also confirmed, thereby giving a helping hand toward hopping and double exchange mechanisms. The permittivity curves followed both symmetric and asymmetric dispersion of relaxation mechanisms, which is best fitted by the Havriliak-Negami functions. The decrement of dielectric relaxation times with thermal energy validates the possibility of temperature-mediated induced entropies and phase lags of dipolar moments. The modulus dispersions curves were fitted following R. Bergman’s formalism, which showed that the dielectric relaxations can be explained as a sum of some Kohlrausch-Williams-Watt
β
KWW
stretched exponents. The extracted numerics of
β
KWW
parameters proved the upper hand of dipolar interactions toward polarizability. The possibility of wider grain wall formation is also validated by it. The ferroelectric and magnetic studies revealed enhancement in the suppression of ferroelectric leakages relative to the parent composite and improved opening of M-H loops, reinforced by enhanced DM hamiltonian interactions due to structural bending and elongation in the double exchange interaction chain, together with the G-type antiferromagnetic phase of the host. The conductivity data fitting was performed by incorporating Dyre’s RFEBM(Random Free Energy Barrier Model) model, where conductivity was verified to be following the mechanisms of hopping jumps through an extended range of free energy barriers.
In this research work, we demonstrate a detailed and systematic investigation of the structural, microstructural, dielectric, electrical, and magnetic properties of the Mg-doped BaFe
0.5
Nb
0.5
O
3
...complex perovskite prepared through the conventional ceramic method. While electron microscopic imaging depicts the heterogeneous distribution of non-uniform shape grains, X-ray diffraction analysis reveals the monoclinic crystal structure of the sample. The elemental analysis by energy-dispersive X-ray spectroscopy confirms the presence of expected elements in the sample. Besides valency identification of the involved elements, the existence of oxygen vacancies is evident from X-ray photoelectron spectroscopy analysis. Dielectric and electrical properties are investigated in terms of dielectric constant, dielectric loss, complex impedance, and conductivity studies. Magnetic analysis reveals that the sample exhibits weak ferromagnetism at room temperature. The obtained results from various characterizations signify the suitability of this sample for modern electronic device-based applications.
Ferroelectric flexible polymer composite films of poly(vinylidene fluoride) (PVDF) with different weight percentages (10.0%, 20.0%, 30.0%, 40.0%, and 50.0%) of (Bi0.5Ba0.25Sr0.25) (La0.5Ti0.5) O3 ...were synthesized by solvent casting method. Analysis using the x‐ray diffractometer and Fourier transform infrared spectroscopy tools revealed the presence of the different phases (α, β) of PVDF. Scanning electron microscope morphology illustrates the homogenous dispersion of ceramics particles in the matrix. The differential scanning calorimetry curve (under 25–400°C) gives the value of melting temperature (Tm=169.98°C) and percentage crystallinity is about 29.45% for 50 wt.% composite. The findings demonstrated that the composite has good thermal stability up to 169.98°C. Dielectric analysis shows ferroelectric and dielectric behavior and also distinguishes α and β phases of PVDF. It was found that the composite film containing 50 wt.% (Bi0.5Ba0.25Sr0.25) (La0.5Ti0.5) O3 had a dielectric constant (εr) of 38 (at 100 Hz) and dielectric loss of 0.059, which are the maximum among the samples. The relative permittivity rises with an increase in filler content due to electrostatics and interfacial polarization between PVDF (CH2CF2 dipole) and ceramic. The real and imaginary part of impedance spectroscopy with frequency (Cole–Cole plots) for composite (10.0–50.0 wt.%) at 25°C are also investigated. The current study provides a fresh perspective on the fact that PVDF‐(Bi0.5Ba0.25Sr0.25) (La0.5Ti0.5) O3 composite system has improved thermal stability and dielectric characteristics.
A polycrystalline ceramic oxide, BaFe2MnO6 was produced through a regular solid-state route. The phase creation in the synthesized substance was investigated through X-ray diffraction (XRD) ...technique. The present material has found with made up of a single phase orthorhombic structure. The electrical properties of the compound were recorded through an LCR meter for a broader range of frequencies and temperatures. This perovskite oxide material possesses a large relative permittivity (ɛr = 1139) and low dielectric loss (tanδ = 0.421) at the ambient atmospheric condition, while the curie temperature arise beyond 450 °C. The resultant dielectric properties of this material assure its promising candidature for feasible applications in smart electronic devices such as dielectric material in ceramic capacitors.
The polycrystalline Bi
1−
x
Gd
x
FeO
3
(BGFO) (
x
=0.0, 0.05, 0.10, 0.15, 0.20) materials were synthesized by a solid-state reaction (mixed oxide) technique. Preliminary X-ray structural analysis of ...the compounds confirmed the formation of single-phase polycrystalline samples. Room temperature scanning electron micrographs of the materials revealed the size, type and distribution of grains on the surface of samples. Studies of impedance, electrical modulus and electric conductivity of the materials in a wide frequency (10–1000 kHz) and temperature (30–500
∘
C) range using a complex impedance spectroscopy technique have provided considerable vital information on contribution of grains, grain boundary and interface in these parameters. A strong correlation between these electrical parameters and microstructures (bulk, grain boundary, nature of charge carrier, etc.) of the materials was established. The frequency dependence of electric modulus and impedance of the material shows the presence of non-Debye type of relaxation.
Polymer composites with high dielectric constant and minimal dielectric losses have wide ranging prospects for advanced applications in the flexible electronics and electrical industry. In this ...study, we used the advantages of carbonaceous hybrid nanofillers to develop a flexible dielectric material. Herein, a set of hybrid nanocomposites were successfully fabricated by incorporating the Ti3C2Tx (MXene) and MWCNTs (multi‐walled carbon nanotubes) hybrid mixture as the conductive moiety into the poly(ethylene‐co‐methyl acrylate) (EMA)/ethylene‐octene co‐polymer (EOC) binary blend as the matrices using solution mixing technique followed by compression molding. As prepared, EMA/EOC/Ti3C2Tx/MWCNTs hybrid composites have been characterized by FTIR (Fourier transform infrared) spectroscopy, XRD (X‐ray diffraction), TGA (thermogravimetric analysis), FESEM (field emission scanning electron microscopy), and DSC (differential scanning calorimetry). We studied the effects of Ti3C2Tx and MWCNTs contents in the hybrid composites on the thermal, dielectric, and electrical properties. Among all the 15 wt% hybrid mixture containing 2 wt% MWCNTs loaded composite has the highest dielectric constant (ℇr = 122.21) and the lowest dissipation loss (tan δ = 0.030) at 100 Hz. The present studies recommend the EMA/EOC/Ti3C2Tx/MWCNTs hybrid composites can be used in smart and flexible electronic storage material.
Highlights
EMA‐EOC blend composites with hybrid Ti3C2Tx/MWCNTs were processed.
2.5 wt% MWCNTs loaded hybrid composite shows excellent thermal stability.
Composite with 2 wt% MWCNTs has ℇ' = 122.21 and tanδ = 0.03 at 100 Hz.
2.5 wt% MWCNTs composite has electrical conductivity of 3.26 × 10−8 Ω−1 m−1.
This composite can be used in smart and flexible electronic storage material.
We have processes a composite filled with dual filler Ti3C2Tx‐MWCNTs reinforced EMA/EOC blend. Their dielectric and thermal behavior have been studied. This can be utilized as a material for energy storage device.
A solid-state reaction procedure was followed to synthesize the BaBi
1.4
Fe
0.6
TiO
6
ceramic. To compensate for the Bi
3+
evaporation during the high-temperature sintering process, more Bi
3+
...content was so selected, further, it adds more promising ferroelectric and dielectric orders. The monoclinic crystal system formation was checked by the X-Ray Diffraction and Rietveld refinement methods. The average crystallite size is 37.46 nm, while the average grain size is 137.28 nm, which implies that a single grain might have contained some single-phase crystallites. The Energy-Dispersive X-Ray spectrum confirmed the sample’s elemental purity. The material belongs to a perovskite phase, which was supported by some appeared usual vibrational modes in the Fourier-Transform Infrared analysis. The UV–Visible absorbance property results cutoff wavelength of 590 nm and the optical direct bandgap E
g
= 2.53 eV. The remanent magnetization of 2P
r
= 0.782µC/cm
2
supports the ferroelectric nature. The room temperature (RT) dielectric parameter at 100 Hz has a higher ɛ
r
(1408) and lower tanδ (0.24) as well as a higher transition (T
d
> 350 °C) and Curie temperature (T
c
> 485 °C). Deviation from the Debye-type relaxation process and semiconducting nature were observed in the sample. The conductivity nature is obedient to the Arrhenius law, which results in dc conductivity activation energy, E
a
= 0.94 eV.
