Large Dielectric Constant Research Articles

Third-order Electrical Conductivity of the Charge-ordered Organic Salt α-(BEDT-TTF)2I3

We performed third-order electrical conductivity measurements on the organic conductor $\alpha$-(BEDT-TTF)$_2$I$_3$ using an ac bridge technique sensitive to nonlinear signals. Third-order conductance $G_3$ is clearly observed even at low electric fields, and interestingly, $G_3$ is critically enhanced above the charge-order transition temperature $T_{\rm CO}=136$~K. The observed frequency dependence of $G_3$ is incompatible with a percolation model, in which a Joule heating in a random resistor network is relevant to the nonlinear conduction. We instead argue the nonlinearity of the relaxation time according to a phenomenological model on the mobility in materials with large dielectric constants, and find that the third-order conductance $G_3$ corresponds to the third-order electric susceptibility $\chi_3$. Since the nonlinear susceptibility is known as a probe for higher-order multipole ordering, the present observation of the divergent behavior of $G_3$ above $T_{\rm CO}$ reveals an underlying quadrupole instability at the charge-order transition of the organic system.

Investigation of thermal stability, structure, magnetic and dielectric properties of solvothermally synthesised SnFe2O4

SnFe2O4 nanoparticles have found wide applicability in recent times. An investigation of the thermal behaviour is important for its utility in dielectric/energy applications that involves heat treatment. The present work reports the synthesis of SnFe2O4 nanoparticles and the investigation of the thermal stability, magnetic and electrical properties on annealing. SnFe2O4 nanoparticles were synthesized by the solvothermal method and characterized using Thermogravimetry, X-ray diffractometry, Scanning and Transmission Electron Microscopy and Vibrating Sample Magnetometry. The spinel structured SnFe2O4 nanoparticles showed superparamagnetic behaviour with MS = 10.5 emu/g and paramagnetic transition at 517°C. On annealing in air between 300°C and 1100°C, the spinel phase was found to be stable until 500°C, but decomposed to tetragonal and hexagonal Fe–Sn oxides beyond 550°C. The resultant oxides were antiferromagnetic or weakly ferromagnetic. Electrical measurements revealed large dielectric constant (∼104) and dielectric loss <9 over a wide frequency range for SnFe2O4 and the decomposed Fe–Sn oxides.

Ultra-high energy storage density of transparent capacitors based on linear dielectric ZrO2 thin films with the thickness scaled up to hundreds nanometers

In this work, a high energy storage density in transparent capacitors, based on linear dielectric ZrO2 thin films, with thickness scaled up to hundreds of nanometers, is reported. Linear dielectric ZrO2 films with a thickness of several hundred nanometers are grown on Sn-doped In2O3 (ITO) electrode layers grown on transparent glass substrates at room temperature. The fabricated ITO/ZrO2/ITO capacitors show excellent dielectric energy storage performance, including a large dielectric constant, low loss and leakage current, and large breakdown strength. Consequently, these capacitors present high energy density and efficiency, as well as robust device endurance. In particular, ultra-high recoverable energy storage density (Wrec ∼ 75.4 J/cm3) and efficiency (η ∼ 88%) are achieved simultaneously in ZrO2 film-based (470 nm thick) capacitors, rivaling those of other lead-free ferroelectric-like and other linear dielectric film capacitors. Moreover, the capacitors show good transparency in the visible range, indicating the potential energy-storage applications in transparent electronics.

2-D Pixel-Based Inversion for Simultaneous Reconstruction of Resistivity and Dielectric Constant From Electromagnetic Logging-While-Drilling Measurements

The dielectric effects are significant in certain circumstances in hydrocarbon exploration and production. Neglecting these effects can result in an inaccurate description of subsurface structure in terms of resistivity estimation and boundary location. However, almost all existing research has ignored the dielectric effects in the inversion process for ultradeep electromagnetic logging-while-drilling (LWD) measurements. As a complement, this article aims to investigate the impact of the dielectric constant on the inversion performance. In this study, we present the possible causes of the appearance of large dielectric constant in formations and discuss the influence of dielectric constant on one set of measurements via the sensitivity study. Besides, a 2-D pixel-based inversion algorithm is introduced for simultaneous determination of resistivity and dielectric constant. Also, the gradient of measurements with respect to interested parameters using the adjoint method is provided and validated. In addition, the capability of the inversion approach is demonstrated with several numerical examples. It is found that accounting for the dielectric constant in the inversion can help to improve the interpretation of electromagnetic measurements in some scenarios, thus enhancing the understanding of the subsurface structures.

The effect of (Ni2+ + Sr2+) co-doping on structure and dielectric properties of Bi1.5MgNb1.5O7 pyrochlores

The dielectric properties of bismuth-based cubic pyrochlore largely depend on the A-site cation. The effect of (Ni2+ + Sr2+) co-doping on the structure and dielectric properties of Bi1.5MgNb1.5O7 (BMN) was investigated. It reveals that the Ni2+ and Sr2+ in the co-doped Bi1.5Mg0.5NixSryNb1.5O7 (BNSN, x = 0.0–0.3 mol%, y = 0.0–0.2 mol%) ceramics preferentially replaced the Mg2+ on the A-site. For the samples with x = 0.3 and y < 0.2, it showed a very low dielectric loss (∼0.0003, 1 MHz). The dielectric loss of BNSN gradually increased with the increase of Sr2+ doping. However, the dielectric constant increased with increasing Sr2+ content. The BNSN exhibited a large dielectric constant (∼166, 1 MHz) at x < 0.3 and y = 0.2. Ni-doping would reduce the oxygen vacancy, which in turn decrease the dielectric loss. While, the increasing dielectric constant is attributed to the high ion polarizability of Sr2+ ions.

Opto‐Electromagnetics and Resonance Activities of Oxalic Acid Embedded Manganese and Cadmium‐Mixed Crystals

AbstractManganese‐mixed barium oxalate (MMBO) and cadmium‐mixed zinc oxalate (CMZO) crystals are fabricated using a gel technique. The foregrounded crystals are characterized by spectroscopic and analytical techniques. Chemical constituents, cationic distribution, functional groups, thermal stability, and degradation behavior of MMBO and CMZO crystals are explored in succession with the aid of energy‐dispersive X‐ray analysis, Fourier transform infrared spectroscopy and thermogravimetric analysis respectively. MMBO crystal embeds a molecular weight of 223.419 (chemical formula Mn0.4607Ba0.5394C2O42H2O), whereas CMZO ingrains by a molecular weight of 212.656 (chemical formula Zn0.6976Cd0.3024C2O42.5H2O). Both the crystals possess band gap energies (Eg ≈ 6 eV), large dielectric constant, leakage resistance in GΩ, capacitance in pF, excellent thermal stability (890 °C), opaqueness to electrical current and paramagnetic (MMBO)/diamagnetic behaviors (CMZO). Surprisingly, in response to alternating emf, crystal capacitors of MMBO and CMZO exhibit very sharp resonance throws at mid radio frequency range showcasing quartz‐like extremely high quality factor. Distinct optoelectric behavior, outstanding thermal stability and special resonance dynamics signal unique applications in communication–micro‐high‐temperature electronics.

Electromagnetic response characteristics of lightweight hierarchical 2D nitrogen-doped graphene@amorphous carbon

Two dimensional (2D) nitrogen-doped graphene@amorphous carbon was constructed by in-situ polymerization of sandwich-like structured polyaniline/graphene oxide composites then carbonization at 650 °C in vacuum. The results revealed that the as-prepared 2D N-doped graphene@amorphous carbon and N-doped amorphous carbon nanorods have almost the same decomposition degree and crystal structure. However larger defective degree and more polar bonds are conducive to enhance the polarization loss capacity, and larger dielectric constant can contribute to prominent conductive loss potential. The standing-wave ratio at 13.325 GHz of 2D N-doped graphene@amorphous carbon is 1.08426 approaching to 1, almost perfect impedance-matching level achieving. HFSS simulations certify phase mutation, group delay and the resonance response between N-doped graphene@amorphous carbon and testing microwave, as well as the stronger microwave loss capacity and better impedance matching. Both of the above make 2D N-doped graphene@amorphous carbon a promising microwave absorbing material. The minimum reflection loss (RL) of nitrogen-doped graphene@amorphous carbon can reach −29.5 dB and the effective absorbing bandwidth (EAB, RL < −10 dB) can reach 5.355 GHz ranging from 12.56 to 17.915 GHz only at a thickness of 2.25 mm.

MCdCl3(M=CH3NH3, (CH3)2NH2): New Hybrid Perovskites with Large Dielectric Constants for Field‐Effect Transistors

Organic–inorganic metal halide hybrid perovskites (OIHPs) have recently noticed a tremendous number of applications in the field of optoelectronics by virtue of such outstanding dielectric properties as the large dielectric constant, the good electrical conductivity, the high capacitance, the low dielectric loss, as well as the low exciton binding energy and the trap density. These are important parameters that enhance the performance of many optoelectronic devices, notably, the components of field‐effect transistors (FETs). Herein, the dielectric investigation of the following single crystals Cd(1) and Cd in large frequency ranges and at different temperatures is mainly focused on. This article draws a comparison between the dielectric performances of the prepared perovskites 1 and 2 and the previously reported results, which shows that these materials exhibit large dielectric constants (103) at low frequencies, leading to structural fluctuations and slow‐moving ions. In addition, the high electrical conductivity (≈2. S), the low dielectric loss (&lt; 0.1) at high frequencies, and the high capacitance (≈5 F ) demonstrate the superior dielectric potential of these promising perovskites in FET technologies. These compounds which have multifunctional roles in new transistor devices can be used as dielectric gates due to their high permittivity.

Hole-Pinned Defect Clusters for a Large Dielectric Constant up to GHz in Zinc and Niobium Codoped Rutile SnO2.

High permittivity materials for a gigahertz (GHz) communication technology have been actively sought for some time. Unfortunately, in most materials, the dielectric constant starts to drop as frequencies increase through the megahertz (MHz) range. In this work, we report a large dielectric constant of ∼800 observed in defect-mediated rutile SnO2 ceramics, which is nearly frequency and temperature independent over the frequency range of 1 mHz to 35 GHz and temperature range of 50-450 K. Experimental and theoretical investigations demonstrate that the origin of the high dielectric constant can be attributed to the formation of locally well-defined Zn2+-Nb4+ defect clusters, which create hole-pinned defect dipoles. We believe that this work provides a promising strategy to advance dipole polarization theory and opens up a direction for the design and development of high frequency, broadband dielectric materials for use in future communication technology.

Large voltage-induced coercivity change in Pt/Co/CoO/amorphous TiOx structure and heavy metal insertion effect

There is urgent need for spintronics materials exhibiting a large voltage modulation effect to fulfill the great demand for high-speed, low-power-consumption information processing systems. Fcc-Co (111)-based systems are a promising option for research on the voltage effect, on account of their large perpendicular magnetic anisotropy (PMA) and high degree of freedom in structure. Aiming to observe a large voltage effect in a fcc-Co (111)-based system at room temperature, we investigated the voltage-induced coercivity (Hc) change of perpendicularly magnetized Pt/heavy metal/Co/CoO/amorphous TiOx structures. The thin CoO layer in the structure was the result of the surface oxidation of Co. We observed a large voltage-induced Hc change of 20.2 mT by applying 2 V (0.32 V/nm) to a sample without heavy metal insertion, and an Hc change of 15.4 mT by applying 1.8 V (0.29 V/nm) to an Ir-inserted sample. The relative thick Co thickness, Co surface oxidation, and large dielectric constant of TiOx layer could be related to the large voltage-induced Hc change. Furthermore, we demonstrated the separate adjustment of Hc and a voltage-induced Hc change by utilizing both upper and lower interfaces of Co.

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.

Constructing a new 2D Janus black phosphorus/SMoSe heterostructure for spontaneous wide-spectral-responsive photocatalytic overall water splitting

Janus MoSSe monolayer with built-in electric dipole, as another emerging two-dimensional (2D) material after MoS2, is predicted to be an ideal photocatalyst for overall water splitting. However, in spite of the excellent hydrogen evolution reaction (HER) activity of Se-surface, the extremely poor oxygen evolution reaction (OER) activity of S-surface hinders the achievement of photocatalytic overall water splitting. Herein, we construct a new 2D van der Waals heterostructure consisting of high-OER-active black phosphorus (BP) and Janus MoSSe monolayer, and demonstrate a new strategy of Janus BP/SMoSe heterostructure to achieve wide-spectral-responsive photocatalytic overall water splitting. The electronic structures and optical properties of two different heterostructures, BP/SMoSe and BP/SeMoS, are systematically investigated via first principles density, exhibiting a type-II band arrangement. Unlike BP/SeMoS, the BP/SMoSe heterostructure shows excellent optical properties, such as a large dielectric constant of 8.14 and a small optical absorption boundary of 0.10 eV. Furthermore, BP/SMoSe heterostructure possesses greater light absorption intensity and a broader light absorption range. It is found that the BP/SMoSe heterostructure exhibits proper band alignment and enhanced intrinsic dipole, which is favorable to obtain high electron-hole separation efficiency. This work provides a feasible strategy of 2D Janus BP/SMoSe heterostructure for approaching almost perfect overall water-splitting photocatalysis.

Dominant Role of Quantum Anharmonicity in the Stability and Optical Properties of Infinite Linear Acetylenic Carbon Chains.

Carbyne, an infinite-length straight chain of carbon atoms, is supposed to undergo a second order phase transition from the metallic bond-symmetric cumulene (═C═C═)∞ toward the distorted insulating polyyne chain (-C≡C-)∞ displaying bond-length alternation. However, recent synthesis of ultra long carbon chains (∼6000 atoms, [Nat. Mater., 2016, 15, 634]) did not show any phase transition and detected only the polyyne phase, in agreement with previous experiments on capped finite carbon chains. Here, by performing first-principles calculations, we show that quantum-anharmonicity reduces the energy gain of the polyyne phase with respect to the cumulene one by 71%. The magnitude of the bond-length alternation increases by increasing temperature, in stark contrast with a second order phase transition, confining the cumulene-to-polyyne transition to extremely high and unphysical temperatures. Finally, we predict that a high temperature insulator-to-metal transition occurs in the polyyne phase confined in insulating nanotubes with sufficiently large dielectric constant due to a giant quantum-anharmonic bandgap renormalization.

Effect of BaTiO3Nanofillers on the Energy Storage Performance of Polymer Nanocomposites

AbstractPolymer nanocomposite is a promising substitute for the charge‐storage dielectric material in capacitors. Barium titanate/polycarbonate (BT/PC) nanocomposite is one of the system due to its comprehensive excellent dielectric properties. As the dielectric response of nanocomposite depends strongly on the size of the fillers, concentration of fillers in the composite system. In this study, BT/PC nanocomposites (BT = 1‐5%) with thickness of 100 µm were fabricated to reveal the effect of the fillers on the energy storage performance of the polymer nanocomposites. Owing to the variable concentration and good dispersibility of the nanofillers, the nanocomposites with small concentration of BT particles show more uniform and denser microstructures. Moreover, with the increase of filler concentration, dielectric results indicate a breakdown strength enhancement in the nanocomposites with BT fillers, which is quite different from the nanocomposites with normal fillers, and therefore leads to the superior energy storage performance. This study demonstrates a strategy of obtaining large dielectric constants and energy densities in ceramic/polymer composites for energy storage device applications.

Superior energy storage performance coupled with excellent electrical characteristics in lead-free Ba0.8Ca0.2TiO3-(Bi0.80Mg0.20) (Ti0.65Mg0.30)O3 ceramics

Multi-layer ceramic capacitors with high recoverable energy storage density and large energy efficiency play a crucial in modern electronic devices. Various ferroelectric ceramic materials with relaxor characteristics and large dielectric constant are the most favorable candidates for achieving superior energy storage performance. Herein, a novel lead-free (1−x)Ba0.80Ca0.20TiO3-x (Bi0.80Mg0.20)(Ti0.65Mg0.30)O3 (BCT-BMT) ceramic materials were prepared by two-stage mechano-chemical activation technique. BMT substitution in Ca modified BaTiO3 has resulted in substantial improvement in microstructural characteristics and subsequently an improvement in energy storage performance in comparison to pure BCT. The introduction of BMT in BCT has resulted in transformation into relaxor ceramics, which is vital for obtaining high recoverable energy storage density and large energy efficiency. In the present investigation, the composition with 0.65BCT-0.35BMT shows a typical relaxor characteristic, large breakdown strength, and a substantially large dielectric constant. As a result of improvement in electrical properties, the composition 0.65BCT-0.35BMT possesses an ultra-high recoverable energy density of 3.09 J cm−3 along with a moderately high energy efficiency of ∼80.15%. The obtained results indicate the effectiveness of BMT substitution on the energy storage properties and excellent compatibility between BCT and BMT phases.

Study on a novel vertical enhancement-mode Ga 2 O 3 MOSFET with FINFET structure

A novel enhanced mode (E-mode) Ga2O3 metal–oxide–semiconductor field-effect transistor (MOSFET) with vertical FINFET structure is proposed and the characteristics of that device are numerically investigated. It is found that the concentration of the source region and the width coupled with the height of the channel mainly effect the on-state characteristics. The metal material of the gate, the oxide material, the oxide thickness, and the epitaxial layer concentration strongly affect the threshold voltage and the output currents. Enabling an E-mode MOSFET device requires a large work function gate metal and an oxide with large dielectric constant. When the output current density of the device increases, the source concentration, the thickness of the epitaxial layer, and the total width of the device need to be expanded. The threshold voltage decreases with the increase of the width of the channel area under the same gate voltage. It is indicated that a set of optimal parameters of a practical vertical enhancement-mode Ga2O3 MOSFET requires the epitaxial layer concentration, the channel height of the device, the thickness of the source region, and the oxide thickness of the device should be less than 5 × 1016 cm−3, less than 1.5 μm, between 0.1 μm − − 0.3 μm and less than 0.08 μm, respectively.

Influence of polarization, multi-valences and multi-coordination of cobalt: Third-order nonlinear, dielectric and Faraday properties of Bi0.5Co1.5S3/high optical basicity glass

In this study, we have successfully grown Co doped Bi0.5Co1.5S3 nanocrystals inside heavy metal oxide diamagnetic 42PbO-48TeO2-10B2O3 glass whose morphology, structure and properties were characterized using various techniques. The optimum parameters for Bi0.5Co1.5S3 nanocrystals formation is 380°C for 10hours. Glasses having different amounts of Bi0.5Co1.5S3presented colors from light yellow to green and pure blue due to the different optical absorption of Co2+ ions in octahedral and tetrahedral coordination units. X-ray diffraction pattern revealed the formation of orthorhombic Bi2S3 nanocrystals in glass and Raman spectra demonstrated modification on structure such as TeO4 → TeO3 and BO → NBO conversion. The red shift in transmission cutoff edge of glasses showed experimental evidence of quantum confinement effect. Due to the high optical basicity system, X-ray photoelectron spectra studies confirmed the co-existence of Co2+, Co3+ and Co4+ which presented characteristic absorption in ultraviolet-visible spectra. The introduction of Bi0.5Co1.5S3 greatly increased the polarizability of glass, resulting in significant improvement on third-order nonlinearity, AC conductivity and dielectric constant. 1% Bi0.5Co1.5S3 doped glass presents giant Verdet constant of 62 rad/T.m at 633nm, promising nonlinear refractive index (5.662 × 10−11 esu) and large dielectric constant (78). This result proved that the synthesis of multivalence states of Co doped Bi2S3 in glass is an efficient method to improve the optical, dielectric and magneto optical performance of glass. Such dilute magnetic semiconductor nanocrystals-glass system has great potential applications in nonlinear, dielectric and magneto optical current sensors and isolators devices.

Demonstration of TiO₂ Based Ultra High-k (k = 30) Metal-Insulator-Semiconductor Capacitor and Its Electrical Properties.

In this paper, we investigated TiO₂ as gate dielectric to achieve the large dielectric constant. The ultra high-k value over 30 was obtained by Capacitance-Voltage measurement of Al/Ti/TiO₂/Si Metal-Insulator-Semiconductor (MIS) capacitor. Among as deposited, rapid thermal annealing (RTA) at 750 °C and 1000 °C, the RTA at 750 °C showed the lowest gate leakage current. It implies that TiO₂ has optimum RTA temperature having the lowest leakage current. When TiO₂ is annealed at 750 °C, the phase of TiO₂ changes to anatase and interfacial layer between TiOx and Si was formed. While TiO₂ is annealed at 1000 °C, the phase of TiO₂ changes to rutile and diffusion of silicon atoms was clearly observed and it causes the silicide formation. Based on measurement data, we proposed the energy band diagram of Al/TiO₂/Si MIS capacitors. This diagram shows that the energy band gap of RTA at 750 °C is expanded while that of RTA at 1000 °C is contracted. In addition, TiO₂ with RTA at 550 °C was tested to confirm leakage current and it shows lower leakage current than RTA at 750 °C as we expected. This result confirmed that optimum RTA temperature of TiO₂ would exist under 750 °C.

Enhanced thermal and frequency stability and decent fatigue endurance in lead-free NaNbO3-based ceramics with high energy storage density and efficiency

Lead-free ceramic capacitors have the application prospect in the dielectric pulse power system due to the advantages of large dielectric constant, lower dielectric loss and good temperature stability. Nevertheless, most reported dielectric ceramics have limitation of realizing large energy storage density (Wrec) and high energy storage efficiency (η) simultaneously due to the low breakdown electric field (Eb), low maximum polarization and large remanent polarization (Pr). These issues above can be settled by raising the bulk resistivity of dielectric ceramics and optimizing domain structure. Therefore, we designed a new system by doping (Bi0.5Na0.5)0.7Sr0.3TiO3 into 0.9NaNbO3-0.1Bi(Ni0.5Zr0.5)O3 ceramics, which simultaneously obtained a higher bulk resistivity by decreasing the grain size and achieved a smaller Pr by optimizing domain structure, thus the better Eb of 530 kV/cm and Wrec of 6.43 J/cm3 were achieved, η was improved from 34% to 82%. Besides, the 0.4BNST ceramics show excellent temperature, frequency and fatigue stability under the conditions of 20–180 °C, 1–100 Hz and 104 cycles, respectively. Meanwhile, superior power density (PD = 107 MW/cm3), large current density (CD = 1070 A/cm2) and discharge speed (1.025 μs) were achieved in 0.4BNST ceramic. Finally, the charge-discharge performance displayed good temperature stability in the temperature range of 30 °C–180 °C. The above results indicated that the ceramics have potential practical value in the field of energy storage capacitor.

Lead-free AgNbO3/poly(vinylidene fluoride‐hexafluoropropylene) antiferroelectric nanocomposite for high energy density capacitor applications

In the past few decades, ceramic/polymer nanocomposites have been extensively studied due to their relatively large dielectric constant, high electric energy density, and large charge–discharge efficiency. Antiferroelectric (AFE) materials possess a low remnant polarization (P r) and relatively high saturation polarization (P s), which can induce higher storage energy density than relaxor ferroelectric materials. In this investigation, AgNbO3-based AFE ceramic nanoparticles were grafted with a layer of poly(methyl methacrylate) (PMMA) to form AgNbO3–g-PMMA nanoparticles and then the obtained nanoparticles were embedded into a poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) matrix to form an AgNbO3–g-PMMA/PVDF-HFP (AN–g-PMMA/HFP) nanocomposite film. After characterization, it was found that the dielectric constant of the AN–g-PMMA/HFP-5 (5% AgNbO3) nanocomposite film was 12.3, which was 43% higher than that of the pristine PVDF-HFP film. The AN–g-PMMA/HFP-5 nanocomposite film exhibited the largest breakdown field of 500 MV m−1 and the highest energy density of 13 J cm−3, which was increased by 32.5% (from 9.82 to 13 J cm−3), as compared with that of the pristine PVDF-HFP film. The AN–g-PMMA/HFP-5 film exhibited a charge–discharge efficiency of 69.5% at 500 MV m−1, which is 9.5% higher than that of the pristine PVDF-HFP film. This AgNbO3-based nanocomposite film shows great promise for AFE nanocomposite for high energy density capacitor applications.