Reduction In Crystallite Size Research Articles

Evaluation of microstructural and nanomechanical performance of spark plasma sintered TiFe-SiC reinforced aluminium matrix composites

Due to the increasing demand for lighter materials with enhanced properties, the upgrade of techniques to improve the production of high-performance composite materials is of great interest in modern technology. The microstructural and mechanical properties of spark plasma sintered aluminium based composites with ferrotitanium (TiFe) and silicon carbide (SiC) reinforcements were investigated. High energy ball milling technique was adopted to effectively disperse the particles SiC and TiFe reinforcements into the matrix of aluminium, and the admixed powders were compacted using spark plasma sintering technique. The specimens sectioned from the sintered compacts were analysed using an X-ray diffractometer (XRD), optical microscope (OM), and field emission scanning electron microscope (FESEM) to understand the microstructural features and phase evolution of the sintered composites. The mechanical properties of the composites were also investigated through hardness, nanomechanical and tribology tests. Results from the microstructural examinations conducted shows that the reinforcement particles were evenly dispersed within the aluminium matrix, as a result of the milling process. Furthermore, all the sintered composites had their microstructural features enhanced, but properties such as hardness, frictional coefficient, and elastic modulus were more enhanced in specimen reinforced with 2%SiC+2%TiFe particles. The reduced crystallite size recorded by the sintered specimens confirmed the effectiveness of the milling process, and powder metallurgy route adopted for fabrication.

The relation between particle size and transformation temperature of gibbsite to αLPHA-alumina

ABSTRACT The transformation of gibbsite to α-alumina occurs in the range 1100 to 1300°C. The higher the calcination temperature, the larger the crystallites and this leads to abnormal grain growth. The main goal of this research was to reduce the transformation temperature of gibbsite to α-alumina by reducing the gibbsite particles size. The sodium content of the gibbsite used in the study was reduced to less than 0.1% by washing it in HCl solution. It was then ground in a fast mill at ambient conditions for different times then calcined at different temperatures. The microstructure, particles size and thermal behaviour of the samples were examined with SEM, XRD, XRF, PSA and STA, respectively. In a sample ground for 180 min, the transformation temperature decreased from about 1300°C to 1150°C. The reduction in the calcination temperature led to a reduction in α-alumina crystallite size from about 77.16 nm to 64.37 nm.

The effect of 3-(triethoxy silyl) propyl amine concentration on surface modification of multiwall carbon nanotubes

The influence of 3-(triethoxy silyl) propyl amine (TESPA) concentration on Multi Wall Carbon Nanotubes (MWCNTs) modification, is experimentally investigated. The MWCNTs modification were performed by 150, 75 and 25 weight percent (wt.%) of TESPA with respect to MWCNTs weight and the properties of the prepared samples were compared with each other and pristine MWCNTs. The MWCNTs silylation has been confirmed by Fourier Transformation Infrared Spectroscopy due to O-H stretching absorption peak disappearing. The 75 wt.% silyl grafted MWCNTs with increasing at about 26.7% in mean value diameters size owns more uniform morphology among the samples based on Scanning Electron Microscopy images. Also, Thermo Gravimetric Analysis shows that this sample has higher thermal stability because of lower weight loss (9.97%) in coupling agent decomposition temperature range at about 119.5–480 °C. Furthermore, X-Ray Diffraction indicates that the mentioned sample has higher level of amorphous structure with 39% reduction in crystallite size in comparison with the pristine MWCNTs. So, the 75 wt.% of TESPA introduced as the optimal concentration for this type of MWCNTs modification.HighlightsIntroduction of silyl compounds as a proper coupling agent to modify the carbon nanotube surfacesDetermination of optimal silyl compounds concentration to modify the carbon nanotube surfaceCristallinity in XRD pattern can determine the success of CNTs grafted with silyl compounds

Facile green route sol–gel synthesis of nano-titania using bio-waste materials as templates

Titania semiconductor is being used in a wide range of fields; however, the poor surface properties and meagre visible light absorption capacity of it stand as barriers for being used as an effective visible light active photocatalyst. To overcome these limitations, various strategies have been adopted, among which the usage of templates has been the topic of research for the past 10 years. Usage of the template during the synthesis of titania increases the surface area by reducing the agglomeration of nanoparticles and also shifts the absorption edge to the visible range. Nowadays, green synthesis has gained substantial attention as an effective, safe and environmentally friendly practice for the synthesis of nano-titania. Bio-waste pista shells, corn pith, and tamarind seeds which are regarded as unproductive have been used in the sol–gel synthesis of Pista Shell Templated Titania (PST), Corn Pith Templated Titania (CPT) and Tamarind Seed Templated Titania (TST). The synthesized templated titania was subjected to morphological, crystallite, surface characteristic and photocatalytic studies. XRD results of synthesized CPT, PST and TST exhibited that they possessed anatase form. The crystallite size of PST, CPT and TST was found to be 12.26 nm, 12.28 nm and 15.55 nm, respectively, proving the reduction in crystallite size than in non-templated titania. Efficient photocatalytic activity of templated titania was observed via the degradation of methyl orange, which proved the larger surface area of templated titania than that of non-templated titania. Pista shells, corn pith and tamarind seeds were found to grant a decisive support in the controlled growth of titania and in photocatalytic applications which stands out as a reason to be looked upon as an effective bio-waste green template in the synthesis of nano-titania.

Structural, morphological and opto-electrical properties of transparent conducting SnO2 thin films: Influence of Sb doping

ABSTRACT Pure and antimony doped tin oxide (Sb:SnO2) thin solid films were synthesised through a simple and low-cost nebulised spray pyrolysis (NSP) route. The influence of Sb doping on the different physical properties of these films was systematically investigated. The results of X-ray diffraction (XRD) study exhibited polycrystalline in nature of all films with tetragonal cassiterite structure of single phase SnO2. XRD analysis also revealed the reduction in crystallite size as well as the grain size observed in scanning electron microscopy (SEM) with Sb doping concentration. The average transmittance of all the films was greater than 73% at the visible wavelength region and the transparency was reduced by Sb inclusion. The direct optical band gap value was the lowest of 3.94 eV for pure SnO2 and enhanced by Sb doping level. The effects of Sb doping concentration on extinction coefficient, refractive index, dielectric constant, optical conductivity and optical density of the films were examined. Photoluminescence spectrum revealed a broad violet emission peak near 390 nm and Sb doping intensified the peak. Both the resistivity and sheet resistance were found to vary in the range of 1.61 × 10−3 Ω.cm to 3.92 × 10−4 Ω.cm and 32.73 Ω/□ to 134.41 Ω/□, respectively with the variation of Sb doping concentration. The highest mobility and carrier concentration were 54.74 cm2/Vs and 7.02 × 1021 cm−3 for undoped and 10% Sb doped films, respectively. However, the figure of merit was found to be maximum of 1.38 × 10−3 (Ω/cm2)−1 for 5% Sb doping concentration among the films.

Role of partial amorphous and disordered stannous ions incorporated hydroxyapatite nanosphere for enhanced electrochemical energy storage application

Tin (Sn2+) ions incorporated hydroxyapatite (HAp) nanospheres are prepared by wet chemical. The Sn2+ ions lead to reduce crystallite size with modified vibration groups. The nanosphere is achieved on incorporation. The surface area and pore diameter are enhanced at low Sn2+ ions (11.29%). The specific capacitance (231 F g-1 at 3 mAg−1) (230%) is augmented at higher incorporation (27.27%) compared to pristine. The 100% cyclic stability up to 800 cycles is achieved. Here, the correlated partial amorphization, atomic disorder and surface properties are realized. Thus, the tin-calcium phosphate demonstrates an outstanding candidate for electrochemical energy storage application.

Synergistic effect of surfactant and saccharin on dispersion and crystal refinement for electrodeposition of nanocrystalline nickel/graphene oxide composite

Homogeneous dispersion of graphene oxide (GO) in nickel sulfamate solution is a significant challenge for electrodepositing high-performance nickel/GO composite coatings. In the present work, three typical surfactants, including anionic surfactant Sodium dodecyl sulfate (SDS), cationic surfactant Cetyltrimethylammonium bromide (CTAB), and non-ionic surfactant Polyethylene glycol (PEG), and saccharin are used to disperse GO nanoparticles and refine crystallite size of nickel/GO composite coating. The synergistic effect of surfactant and saccharin is revealed from the perspectives of dispersion, crystal refinement and their impact on mechanical and tribological properties of nickel/GO composite coating. Our results indicate that PEG possesses the optimal dispersibility to GO dispersion, followed by CTAB and SDS. The addition of saccharin in electrolyte does not affect the surface charge of GO particles, but it helps to reduce the particle size of GO and thus reduce potential reaggregation. Additionally, PEG shows the most significant reduction of crystallite size from ~35 nm to ~19 nm. The synergetic effect of surfactant and saccharin is indicated by increasing the concentration of saccharin from 0 to 0.2 g/L with various surfactants, where the overall crystallite size is gradually reduced. Moreover, the hardness of PEG-GO and CTAB-GO coatings is remarkably increased by 252% and 312%, respectively, compared to pure nickel coating. The increased hardness is due to the synergistic effect of crystal refinement from both additions of GO and saccharin. The tribological test indicates that the PEG-GO coating can achieve the maximum reduction of friction coefficient with 0.15 with the addition of saccharin of 0.2 g/L.

Synthesis and characterization of magnetically separable Zn1-xCoxFeMnO4 nanoferrites as highly efficient photocatalyst for degradation of dye under solar light irradiation

Cobalt doped magnetically separable Zn1-xCoxFeMnO4 (x = 0.0, 0.25, 0.50, 0.75, 1.0) nanoparticles of ferrite were synthesized using auto-combustion process of sol-gel utilizing glycine as a fuel. The powder XRD and Rietveld refinement studies showed that all of the samples developed a single-phase cubic spinel system. The morphological investigations demonstrate the sphere-like nanostructures, which get distorted after an increase in the concentration of cobalt. A transformation from superparamagnetic activity to ferrimagnetic character has been reported with the introduction of Co2+. As synthesized ferrite nanoparticles have demonstrated an improvement in coercivity with lower density magnetization with reduced crystallite size. A rise in the remanence ratio were observed with the Co2+ content. The optical characterization shows a blue shift in the band gap with increase of Co2+. Considering the band structure in the visible region, the photocatalytic activity of as-synthesized Zn1-xCoxFeMnO4 photocatalysts for degradation of methylene blue under natural sunlight was investigated. The Zn0.25Co0.75MnFeO4 ferrite demonstrated more than 99% degradation of MB dye within 20 min. The effect of catalyst loading, pH, and stability of photocatalyst were studied.

Tetragonal Distortion Due to the Jahn–Teller Effect and Coercivity of CuₓCo1–x Fe₂O₄ Synthesized at Various Annealing Temperatures

The crystal structure and magnetic properties of Cu x Co1– x Fe2O4 samples synthesized by a solid-phase reaction method at various annealing temperatures ( ${T}_{\mathrm {a}} =1073$ –1223 K) were investigated. Tetragonal distortion due to the Jahn–Teller effect of Cu2+ ions was observed in the ${x} =0.8$ sample synthesized at ${T} _{\mathrm {a}} =1223$ K. As the magnetic anisotropy constant is enhanced by such distortion, the Cu concentration dependence of the coercivity value ${H} _{\mathrm {c}}$ exhibits a maximum. A decrease in ${T} _{\mathrm {a}}$ caused the enhancement of tetragonal distortion and the reduction of crystallite size. As a result, the largest value of ${H} _{\mathrm {c}} = 2100$ Oe was obtained for the ${x} =0.8$ sample synthesized at ${T} _{\mathrm {a}} =1073$ K. It is clear that the control of both the Cu concentration and annealing temperatures during synthesis is important to obtain large coercivity in Cu x Co1– x Fe2O4.

Effect of Ta content and sintering temperature on characteristics of nanocrystalline Cu-Ta nanocomposite

In this study, the microstructural, physical and mechanical properties of the nanocrystalline Cu-Ta material synthesized by mechanical milling and subsequent sintering were investigated affected by Ta content and sintering temperature. Scanning electron microscope and X-ray diffraction results showed that increasing Ta content from 1 to 5 wt% changed the material behavior during milling and resulted in reduction of powder particle size and crystallite size. For the sintered specimens, addition of Ta decreased the electrical conductivity due to reduced density and increased electron scattering effect while micro-hardness of Cu matrix was promoted. The higher sintering temperature about 850 °C also increased density and provided more segregation of Ta which was led to improvement in both micro-hardness and electrical conductivity of Cu-Ta composite. In addition, a comparison between sintering process at 850 °C by SPS method and conventional cold pressing- sintering revealed that SPS has a high potential to enhance physical and mechanical properties.

Fabrication of bulk τ MnAl–C magnets by hot-pressing from ε-phase gas-atomized and milled powder

Isotropic nanocrystalline MnAlC particles with quasi-spherical shape were synthesized by gas-atomization being afterwards milled for a short time of 60 s. Gas-atomized and milled particles were compacted by the hot-pressing method to obtain bulk MnAlC magnets. An adequate combination of the parameters during hot-pressing made it possible to fabricate bulk MnAlC magnets with a simultaneous transformation of ε-phase into the ferromagnetic τ-phase. The study has allowed for correlating the morphology, microstructure and magnetic properties of the bulk magnets obtained from the different powder samples. Hot-pressing experiments performed on milled ε-phase based powders resulted in an increased coercivity as a consequence of a reduced crystallite size (about 25 nm), induced strain (about 0.40%) and the formation of both β-Mn phase and Mn3AlC. This single-step approach has been compared with a two-step process comprising annealing of the gas-atomized ε-phase to develop the τ-phase as a first step followed by compaction via hot-pressing in a second step. Comparable magnetic properties obtained for the bulk magnets resulting from this two-steps route validates the single-step approach followed in this study. This work shows that gas-atomization, flash-milling and hot-pressing of ε-phase MnAlC powder is an efficient path towards the fabrication of bulk τ-MnAlC magnets.

Wear mechanisms identification using Kelvin probe force microscopy in TiN, ZrN and TiN/ZrN hard ceramic multilayers coatings

Mechanical and tribological properties of titanium nitride, zirconium nitride, and (TiN/ZrN)n multilayers were studied to examine the potential of Kelvin probe force microscopy (KPFM) to identify wear mechanisms. Crystalline structure, chemical composition, residual stress, and the mechanical properties showed that the coatings are iso-structural polycrystalline multilayers, with a reduction of grain size, crystallite size, and compressive stress; however, hardness increased with increase in the number of the bilayers. Pin-on-disc test was used for tribological evaluation, and wear tracks were analyzed using field-emission scanning electron microscopy/energy dispersed spectroscopy (FE-SEM/EDS) and KPFM. The increase in mechanical properties generated predominantly abrasive wear mechanisms. Abrasive and adhesive wear mechanisms differentiated by KPFM demonstrated that fragile wear mechanisms presented differences in capacitance and surface potential and that the method is sensitive when the adhered material presents differences in chemical composition. We have demonstrated KPFM to be a promising technique to study tribo-oxidation processes, providing experimental evidence to understand the wear mechanisms at nanometric scales.

Polaron transport mechanism in maricite NaFePO4: A combined experimental and simulation study

We report, for the first time, systematic investigations on electronic properties of maricite NaFePO4 with different crystallite sizes by a combined experimental and theoretical approach. Ac impedance spectroscopy has been used to study the polaron transport behaviour in maricite NaFePO4 structure with different crystallite sizes over a wide range of temperatures. With the decrease in crystallite size, we observe a polaronic conductivity enhancement of approximately an order of magnitude at the nanoscale level as compared with its bulk counterpart. The temperature dependent dc conductivity has been analysed within the framework of the Mott model of polaron hopping and various physical parameters relevant for the polaron hopping process were extracted. Additionally, by introducing an approximated Mott model with calculated hole polaron migration barrier from density functional theory, we evaluated the polaronic conductivity as function of crystallite size in fair agreement with experimental data. The enhanced polaronic conductivity with crystallite size reduction is found to be due to the combined effect of increased polaron concentration, reduced hopping length, and lowered migration barrier.

Lignocellulosic hydrogel from recycled old corrugated container resources using ionic liquid as a green solvent

Lignocellulosic hydrogels are valuable bio-products that have been considered widely in recent investigations. Also, application of low value recycled fibers for high value added products can be of much interest. In this respect, current research has focused on producing hydrogel from recycled old corrugated container (OCC) resources, using 1-butyl-3-methyl-imidazolium chloride ionic liquid (IL) as a green solvent. The results indicated that the IL successfully dissolved OCC fibers, allowing the production of lignocellulosic hydrogel. Considering total water absorption amount as a main criterion for evaluation of hydrogels, the fabricated hydrogel showed promising results (up to 4700% water absorption). X-ray diffraction analysis confirmed obvious reduction in cellulose material crystallinity and crystallite size as a result of the process. Field emission scanning electron microscopy also demonstrated the microstructure of the hydrogel, pore size and shape in the hydrogel, which well supported the laboratory research results. Furthermore, the effect of processing parameters showed that specimens washed with distilled water as the anti-solvent resulted in the highest water absorption. Infrared spectroscopy can be used to suggest the presence of more lignin content in the hydrogel washed with ethanol. Moreover, the best water re-absorption results were observed for the hydrogel washed with distilled water.

Experimental and first-principles study of defect-induced electronic and magnetic properties of ZnO nanocrystals

We investigate defect-induced electronic and magnetic properties of zinc oxide (ZnO) nanocrystalline powders prepared by mechanical milling. The average crystallite size decreases as the milling time is increased but the wurtzite structure is stable even after 60 hours of milling. The structural properties are characterized by X-ray diffraction and transmission electron microscopy. The chemical composition of pure unmilled and as-milled powders is determined by X-ray photoelectron spectroscopy. Raman scattering spectra were analyzed to find evidence of crystallinity and defect structures in the milled powders. The results obtained from electronic paramagnetic resonance studies demonstrate that the defects are due to both oxygen and zinc vacancies. Since defect-induced magnetism has potential application in spintronic devices, we measured the M-H loops of ZnO powders at different temperatures. We observed that there is a transition from paramagnetic to ferromagnetic behavior due to the vacancies caused by the crystallite size reduction. We also calculated the band structures and density of states within the framework of density functional theory with Hubbard U correction to understand the electronic properties of ZnO for both pure crystals and crystals with defects. A simple mechanical milling process can produce a crystallite size of approximately 10 nm after 40 hours of milling, and the resulting significant changes in electronic properties favor superior application in devices as compared with the bulk. This change of intrinsic properties in ZnO is largely due to the size effect and the increase of defect density.

Performance evaluation of optimized leaf-shaped two-dimension (2D) potassium doped CuO nanostructures with enhanced structural, optical and electronic properties

The present work reports synthesis of pristine and potassium (K) doped cupric oxide (Cu1-xKxO, where x = 0.02, 0.04, 0.06 and 0.08) nanoleaves (CuO-NLs) with preferred growth along [010] plane via co-precipitation synthesis route. The XRD and Raman results exhibited potassium generated defects, oxygen vacancies and strain in CuO lattice due to remarkable difference in the ionic radii, and Pauling electro-negativity of K+ and Cu2+ ions. These defects in the crystal lattice of CuO lead to reduction in crystallite size from 31 nm to 22 nm, without altering the monoclinic structure of CuO. The TEM images revealed the formation of leaf-shaped two-dimension (2D) CuO nanostructures. FTIR results further confirmed the presence of the Cu–O stretching vibrations in doped samples. In the optical properties, diffuse reflectance (DR) and photoluminescence (PL) measurements were performed. DR spectra were used to determine the bandgap and it decreased in the doped samples. A wellspring of emission was observed and the influence of doping concentration on PL properties was systematically studied. Impedance spectroscopy study revealed that the presence of K+ ion boosts the ac conductivity and dielectric constant up-to ~104. Nyquist plot confirms the major contribution of grain boundary to the total capacitance and resistivity of the samples. As-synthesized K doped CuO nanostructures due to enhanced structural, optical and electronic properties hold high potential of applications in various fields.

Facile and inexpensive synthesis of Ag doped ZnO/CNTs composite: Study on the efficient photocatalytic activity and photocatalytic mechanism

In present study, an effective photocatalytic activity for Reactive Black GR and metronidazole degradation was evaluated using microwave-assisted prepared Ag doped ZnO, ZnO/CNTs and Ag doped ZnO/CNTs composites as photocatalyst under visible and sunlight irradiation. The photocatalysts were extensively characterized using a variety of standard tools. The results of XRD and XPS analysis identified the presence of Ag in synthesized composites. The introduction of Ag into the lattice of ZnO deteriorated crystal growth with the reduction of crystallites size, suppressed electron-hole pair's rate and shift in the optical absorption response from UV to visible region due to its surface plasmon resonance effect. The presence of CNTs enhanced the specific surface area of the composites meanwhile content of hydroxyl oxygen at the surface reduced concurrently, that increased the surface hydroxyl groups in the framework of ZnO. Moreover, CNTs acted as electron sink to significantly reduce the photocorrosion of ZnO, consequently improving the photostability of the synthesized samples. An appropriate amount of Ag (2 wt%) and CNTs (2 wt%) (AZC1 composite) was measured to be an optimized composition in accordance with the highest efficiency of the photocatalytic activity. The photocatalytic activity of AZC1 composite for the degradation of Reactive Black GR was measured to be 100% within just 30 min of solar light irradiation and 120 min of visible light illumination, while the corresponding metronidazole degradation was achieved within 40 min of solar light irradiation and 120 min of visible light illumination. A photocatalytic mechanism was proposed to explain the increased photocatalytic performance of the synthesized photocatalysts. This work represents an effective strategy to enhance the photocatalytic activity of ZnO and provides information to synthesize facile, inexpensive and eco-friendly Ag doped ZnO/CNTs photocatalysts.

The Effect of B and Si Additions on the Structural and Magnetic Behavior of Fe-Co-Ni Alloy Prepared by High-energy Mechanical Milling

Nanocrystalline Fe50Co25Ni15X10 (X = Bamorphous, Bcrystalline, and Si) powdered alloys were prepared by mechanical alloying process. Morphological, microstructural, and structural characterizations of the powders milled several times were investigated by scanning electron microscopy and X-ray diffraction. The final crystallographic state strongly depends on the chemical composition and the grinding time; it can be single-phase or two-phase. The crystallite size reduction down the nanometer scale is accompanied by the introduction of high level of lattice strains. The dissolution of Co, Ni, B (amorphous and crystalline), and Si into the α-Fe lattice leads to the formation of highly disordered Fe-based solid solutions. Coercivity (Hc) and the saturation magnetization (Ms) of alloyed powders were measured at room temperature by a vibration sample magnetization. The magnetic measurements show a contrasting Ms and (Hc) in all alloy compositions. Conclusively, soft magnetic properties of nanocrystalline alloys are related to various factors such as metalloid addition, formed phases, and chemical compositions.

Low temperature synthesis and effect of Co doping on structural, optical and dielectric properties of CuCrO2 hexagonal nanoplates

In this research work, delafossite oxide CuCrO2 and its different Co doped compositions CuCr1-xCoxO2 (x = 0.05, 0.1, 0.15) were successfully synthesized by low temperature hydrothermal method. X-ray diffraction (XRD) confirmed the formation of CuCrO2 nanostructures with hexagonal structure having crystallite size less than 100 nm. The XRD peaks also confirmed that the fraction of Cr ions are perfectly replaced by the Co ions in the lattice structure. The crystallite size was found to decrease with increasing the doping concentration. The formation of nanoplates with hexagonal morphology was studied by using scanning electron microscope (SEM). The Fourier transform infrared spectroscopy (FTIR) was employed to analyze the occurrence of various functional groups, stretching and vibrational modes. Tauc's relation was used to calculate the optical band gap (Eg) of the samples from the absorbance spectra. Eg was observed to increase from 3.61eV to 3.95 eV which may be attributed to the reduction in crystallite size as a result of Co doping. The doping concentration also increases the density of grain boundaries which in turn induced the lattice strain in the crystal structure. The interplanar spacing d was observed to increase from 2.489 Å to 2.508 Å resulted due to induced strain. A maximum strain of 0.0132 was found in CuCr0.85Co0.15O2. The impedance and dielectric dispersion of the material were measured using LCR meter. The Cole-Cole plots represent the perfect dielectric behaviour of these materials indicating the pre dominant grain boundary resistance. The dielectric constant showed the increasing behaviour with Co doping concentration. Our results show that manipulation of the band gap and dielectric properties of CuCrO2 nanoplates with doping of Co ions can broadly enhance the efficiency and the applications of these oxide materials.

Enhanced electrical conductivity and multiferroic property of cobalt-doped bismuth ferrite nanoparticles

Multiferroic pure and cobalt-doped bismuth ferrite nanoparticles were synthesized by sol–gel method. The X-ray diffraction study showed a distinct crystalline phase with rhombohedral R3c structure. Rietveld refinement confirmed the reduction of crystallite size from 68 to 45 nm in doped BFO. Transmission electron microscopy was performed to confirm the morphology and lattice constant of the pure and cobalt-doped bismuth ferrite nanoparticles. The results of lattice constant have also been compared with the XRD results. Dielectric properties such as resistance, reactance, impedance, and resistivity were significantly decreased in doped BFO to 7.5 MΩ, 14 MΩ, 17 MΩ, 3.7 MΩ-m, respectively, at 100 Hz with concurrent increased conductivity of 0.184 (S/m) × 10–3 at 10 MHz. The ferroelectric properties of pure and doped samples exhibited significantly enhanced maximum polarization and coercive field in doped BFO of 16 µC/cm2 and 6.2 kV/cm, respectively, at an applied field of 15 kV/cm. Ferromagnetic measurements of synthesized cobalt-doped BFO nanoparticles displayed a substantial improvement in saturation magnetization and coercive force of 7.07 emu/gm and 0.9 kOe, respectively. The important enhancement of magnetic properties with moderate value of coercive field of the cobalt-doped samples may have potential applications in spintronics and memory devices.