Microwave-assisted Combustion Research Articles

Temperature-dependent variation in ammonia sensing properties of ZnO-GO nanocomposites

Industrialization has caused significant environmental and health risks due to the emission of hazardous gases like ammonia. This study investigates the temperature-dependent gas sensing properties of a ZnO-GO nanocomposite synthesized via microwave-assisted combustion. The ammonia sensor, tested from 25 °C (room temperature) to 200 °C, showed its highest sensitivity (72 %) at 100°C for 100 ppm ammonia. It achieved a response time of 94 seconds and a recovery time of 58 seconds. These results demonstrate the potential of ZnO-GO nanocomposite sensors in reducing ammonia-related risks in industrial environments.

Sodium yttrium fluoride doped with Er3+ ions for thermally and non-thermally coupled nano-thermometry and IR detection applications

Microwave-assisted combustion synthesis approach was adopted to prepare sodium yttrium fluoride doped with erbium (NaYF4: Er3+) nanoparticles. Powder x-ray diffraction study confirmed the formation of mixed phase of NaY1-xF4: xEr3+ (x = 1, 3, 5, 7 and 9 mol%) sample with cubic and hexagonal phases (predominant). Three characteristic emission peaks appearing at 526, 546 and 670 nm were attributed to the transitions 2H11/2, 4S3/2 and 4F9/2 to 4I15/2 respectively which are characteristic emissions of Er3+ ions when excited with 980 nm radiation. The optimal dopant concentration was determined as 7 mol% of Er3+ ions in yellowish-green region, and the asymmetric ratio was also calculated. The synthesized up-converting sample follows two-photon process for excitation which was confirmed by power law by varying pump-power in the range of 49–143 mW. The thermally and non-thermally coupled levels attributed to the transitions (2H11/2 and 4S3/2), (2H11/2 and 4F9/2) of Er3+ ions were employed to study the temperature sensing which was recorded in 300–550 K and the relative sensitivities were evaluated to be 0.92 and 0.58 %K−1 correspondingly. The significant thermal sensitivity of the synthesized phosphor materials promises its possibility in optical thermometry applications. The synthesized sample when excited with 980 nm laser radiation produced emission in the visible region which facilitates the utilization of sample as infrared (IR) detector. In the purview of solid-state lighting, the luminous efficiency and luminous efficacy of radiation were evaluated as 23.57 % and 161 lm/Wop respectively. The optical thermometry, IR detection and light generation capabilities of the hexagonal-phased sodium yttrium fluoride doped with erbium (NYF:Er) ions are demonstrated with the obtained results.

Structural, morphological, and optical investigations of Mn-doped LaAlO3 perovskite obtained by microwave-assisted combustion and rapid calcination at low temperature

In this work, LaAlO3 perovskite was doped with 1, 2, 3, 5, 8, and 13 mol% of Mn using the microwave-assisted combustion method. The powders produced were heat treated at 700 °C and 900 °C for 10 min in an adapted microwave oven and then characterized by Thermogravimetric analysis (TG/DTG) and Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD) and Rietveld refinement, X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared Spectroscopy (FTIR), Raman, Ultraviolet–Visible Reflectance (UV–Vis), Field Emission Scanning Electron Microscopy (FE-SEM) and Energy Dispersive X-ray Spectroscopy (EDS). The materials produced doped with the highest concentration of Mn (13 %) showed a single-phase reduced crystallite size compared to the pure sample. The unit cell volumes increased compared to the pure material, while the oxidation state of the dopant was mainly Mn3+. The refinement data for the volume of the different polyhedral that comprise the LaAlO3 unit cell revealed a local change at both sites, which may also indicate Mn substitution at the A site. The heat treatment temperature did not change significantly, demonstrating the method's efficiency in producing perovskites at temperatures and times below those reported in the literature. The morphology observed was porous and irregular agglomerates, and the bandgap was 2.90 eV.

Robust luminescent material with superior color purity: Sm3+ ion-doped CaAl4O7 phosphor synthesized in a cost-effective approach for solid-state lighting applications

This work reports the synthesis of Sm3+ ion doped calcium dialuminate phosphor by microwave-assisted combustion synthesis technique. Phase purity and the crystal structure of the phosphors were affirmed by PXRD analysis and was found to have monoclinic structure. SEM study was performed to analyze the surface morphology. FTIR study clarifies the existence of functional groups. The optical bandgap of 4.43 eV was determined for CaAl4O7:Sm3+ (x = 0.03) sample. The emission spectra of the sample recorded upon excitation at 403 nm suggest orange color emission around 601 nm pertaining to the transition 4G5/2→6H7/2 of Sm3+ ions. The optimal dopant concentration was established at 3 mol%. CIE chromaticity coordinates of (x = 0.6029, y = 0.3964) were established for the optimized sample. Correlated color temperature of 1620 K demonstrates the emission of light in warmer region. The superior color purity of 99.21 % and color rendering index of 77 for the optimized phosphor material was manifested. The photoluminescence (PL) decay time (for Sm3+ concentration = 0.03 mol) was found to be 0.73 ms. Thermal stability of the sample was investigated and the activation energy was determined to be 0.152 eV by temperature-dependent PL study. To explore the lighting ability of the phosphor, phosphor-in-glass (P-i-G) material was fabricated. CaAl4O7:Sm3+ (x = 0.03) based P-i-G material validates excellent luminous efficacy (360 lm/W) and luminous efficiency (52.70 %) which affirms its practical applications.

Experimental Investigation of Microwave-Assisted Kerosene Supersonic Combustion

ABSTRACT The microwave-assisted kerosene combustion in supersonic flow was invested experimentally using a novel microwave-flame coupling method. The experiment used a direct-connected system, with a horn antenna employed to introduce microwaves into the combustion chamber, generating a traveling wave within the cavity. The microwave field simulation results confirm this coupling method’s feasibility. The experimental results showed that with the influence of the microwave, the flame’s stable position moved upstream by 7.4 mm. The average velocity of flame propagation increased by 64% upstream of entering the cavity and by 61% upon exiting it. The specific impulse of the scramjet was increased by about 4% under a 700W continuous microwave. In the presence of hydrogen, there was a significant increase in the excitation of NO and N2. However, in hydrogen-free combustion processes, the enhancement of radicals was considerably less compared to ignition processes, suggesting a close correlation between microwave-assisted combustion and hydrogen. These experimental results validate the feasibility of the microwave-combustion coupling method, representing a novel exploration into microwave-assisted kerosene combustion that aligns more closely with the practical application scenarios of scramjet engines.

Revelation of luminescence-thermometry, light generation in first biological window and IR detection capabilities of sodium yttrium fluoride co-doped with Yb3+ and Er3+ ions synthesized by low-cost approach

Microwave-assisted combustion synthesis approach is adopted to prepare sodium yttrium fluoride co-doped with ytterbium and erbium (NaYF4: Er3+/ Yb3+) nanoparticles. PXRD confirms the formation of mixed phase (cubic and hexagonal) of the NaYF4: Er3+/ Yb3+ crystal lattice. It is determined that the cubic phase dominates over the hexagonal phase. Three characteristic emission peaks appearing at 523, 544 and 672 nm are attributed to the transitions 2H11/2, 4S3/2 - 4I15/2 and 4F9/2 - 4I15/2 respectively which is character of Er3+ ions, confirming the potential in first biological window applications. The optimal dopant concentration is found and the asymmetric ratio is calculated. Strong up-conversion emission has been observed in the sample in the yellowish-green area when excited with 980 nm radiation. The life time of the 4S3/2 (green) and 4F9/2 (red) levels are found to be 1.187 and 0.472 ms respectively. The emission occurring in the synthesized sample follows the two-photon process which is confirmed by double log graph of intensity and pump-power. Thermal sensitivity is recorded in the range of 300–540 K. The thermally and non-thermally coupled levels attributed to the transitions (2H11/2 and 4S3/2) to (2H11/2 and 4F9/2) of Er3+ ions which are employed to study the temperature sensing. Higher relative sensitivities in both thermally and non-thermally coupled levels were observed in the samples with their values being 1.33 % K−1 and 1.81 % K−1 correspondingly. The significant thermal sensitivity of the synthesized phosphor materials improves its possibility in optical thermometric applications. Further to study the light-emitting abilities of the prepared phosphor, a phosphor-in-glass structure was fabricated using a borate-based glass system. The photometric parameters such as luminous efficacy of radiation and luminous efficiency were obtained to be 331 lm/Wopt and 48.46 % respectively. The prepared compound exhibits superior IR sensing which is evident upon exposure of the fabricated P-i-G to 980 nm radiation. The performed studies authenticate the capabilities of the cubic phase NYF in optical thermometry, light generation and IR detection abilities.

Novel Tb³⁺-Doped LaAl₂B₄O₁₀ phosphors: Structural analysis, luminescent properties, and energy transfer mechanism

This study explores the structural and luminescent properties of terbium (Tb³⁺)-doped lanthanum aluminium borate (LaAl₂B₄O₁₀, abbreviated as LAB) phosphors, a novel host lattice for Tb³⁺ doping. LAB:Tb³⁺ phosphors, with varying dopant concentrations, were synthesized using a microwave-assisted combustion synthesis approach and characterized using X-ray diffraction (XRD), Rietveld refinement, and photoluminescence spectroscopy at both room and low temperatures. The structural analysis confirmed the hexagonal crystal structure of LAB and revealed successful incorporation of Tb³⁺ ions without altering the fundamental lattice. Luminescence studies demonstrated that the LAB:Tb³⁺ phosphors show strong green emission primarily attributed to the 5D4→7F5 transition of Tb³⁺. The optimal doping concentration was determined to be 5 wt% Tb³⁺, which provided maximum luminescence efficiency. This concentration also allowed for a critical study of energy transfer mechanisms within the phosphor, revealing dipole-dipole interactions with a critical distance of 9.80 Å between Tb³⁺ ions. Additionally, the CIE chromaticity coordinates of LAB:0.05 Tb³⁺ were precisely determined to be (0.289, 0.4460), indicating the potential for high-quality green emission suitable for solid-state lighting and display technologies. This work not only demonstrates the potential of LAB:Tb3+ as a highly efficient green luminescent material, but also sheds light on the mechanisms responsible for energy transfer and concentration quenching.

Zn-doped nano-Cr2O3 catalyst for fluorination of chlorinated light olefins

A series of Zn-doped nano-Cr2O3 catalysts were prepared by the microwave-assisted combustion method, and the catalysts were successfully applied to the fluorination of 1, 1, 2, 3-tetrachloropropene to synthesize 2-chloro-3, 3, 3-trifluoropropene, and the fluorination of vinylidene chloride to vinylidene fluoride using anhydrous hydrogen fluoride, which is much more efficient than catalyst reported in literatures. By XRD, XPS, and NH3-TPD, it was confirmed that the doping of a small amount of Zn did not have a great influence on the crystal structure of the catalyst but had a great influence on the acidity of the catalyst surface, which increased the number of weak acids and medium acids on the catalyst surface. In addition, the addition of a small amount of Zn could increase the content of high-valent chromium and produce more CrOxFy active centers. As the number of acid sites increases, it provides adsorption centers for chlorine-containing molecules, and the increase of CrOxFy active centers promotes the reaction. They work together to improve the catalytic performance of the catalyst.

Synthesis and Exploring structural, magnetic, morphology and optical properties of La2−xAlxCuO4 (0 ≤ x ≤ 0.25) perovskite nanoparticles by microwave-assisted combustion method

La2CuO4 perovskite nanoparticles doped with aluminum were synthesized through the microwave-assisted combustion technique. Comprehensive studies on the structural, magnetic optical, functional and morphological properties were conducted using various techniques, including XRD, EDX, VSM, DRS-UV, FT-IR and FESEM respectively, .The XRD patterns of pristine La2CuO4 and Al-doped La2CuO4 unequivocally validated the exclusive development of a perovskite structure, devoid of any impurities. Nevertheless, the augmentation in Al3+ content (x = 0–0.25) induced a noteworthy phase shift from orthorhombic to cubic configuration. The average crystallite dimensions spanned from 54 to 41 nm. Distinct FT-IR bands at approximately 687 and 434 cm-1 were intricately linked to the La-O and Cu-O stretching modes inherent to the orthorhombic La2CuO4 phase. The energy gap determined through the Kubelka–Munk (K–M) methodology, experienced an elevation concomitant with the heightened Al3+ content (1.67–1.72 eV), attributable to quantum confinement phenomena. Within the La2-xAlxCuO4 (x = 0 to 0.25) system, the genesis of nanoscaled crystallized grains, interspersed with pores resulting from the amalgamation of grains, was evident. Analysis of hysteresis curves unveiled the emergence of soft ferromagnetic behavior at ambient temperature.

Microwave-assisted combustion synthesis and characterization studies of novel dysprosium doped yttrium calcium borate (Dy3+: Y2CaB10O19) phosphor materials for efficient white light applications

Micro-wave assisted combustion synthesis technique was adopted to synthesize the dysprosium-doped yttrium calcium borate xDy3+: Y(2-x) CaB10O19 (Dy:YCB) polycrystalline phosphor materials with varying concentrations (x = 1, 3, 5, 7 and 9 mol %) for the first time. The formation of phase, crystal structure was analyzed by x-ray diffraction study and was affirmed to be formed pertaining to the monoclinic crystal structure (a = 11.475 Å, b = 6.345 Å, c = 9.223 Å and α = γ = 90°, β = 91.83°) with C2 space group. The absorption capability of the prepared samples was investigated by UV-DRS spectroscopy and the optical band gap was found to be 5.28 eV. FTIR study validated the presence of functional groups and their molecular vibrations. The excitation wavelength of the synthesized samples was found to be 350 nm from photoluminescence excitation (PLE) spectra. The PL emission spectra were recorded to authenticate the emission wavelengths and found to possess two emission peaks at 480 nm (blue) and 577 nm (yellow) contributed by the Dy3+ ions. The optimized dopant concentration of dysprosium ion was fixed at x = 0.07 to avoid the concentration quenching effect. The chromaticity co-ordinate of optimized sample was determined to be x = 0.3188, y = 0.3233 which are closer to ideal white light co-ordinate. The color temperature was determined to be 6209 K, which occurs in the cool white light region. Luminous efficacy of radiation (LER) was determined to be 269.31 l m/Wopt for the optimal phosphor. The luminous efficiency for the optimal phosphor was determined to be 40%. Color rendering index (CRI) of the optimal sample was evaluated to be 77. Internal quantum yield (IQE) of the optimal sample was determined to be 50.58 %. The phosphor materials have excellent thermal stability as validated from the temperature dependent PL measurements.

Using different ratios of glycine to citric acid as fuel mixture in microwave-assisted combustion synthesis of Eu-doped Y2O3–Gd2O3 nanophosphors

Using different ratios of glycine to citric acid as fuel mixture in microwave-assisted combustion synthesis of Eu-doped Y2O3–Gd2O3 nanophosphors

Influence of Mn, Mg, Ce and P promoters on Ni-X/Al2O3 catalysts for dry reforming of methane

In this work, the performance of a series of nickel catalysts supported on alumina containing the promoters Mg, Mn, Ce and P was evaluated against the dry reforming of methane (DRM). Alumina support was obtained quickly and simply through the microwave-assisted combustion method using low levels of urea. The catalysts were characterized by XRD, TPR, FTIR and XRD in situ, proving that successive hydration and heat treatment steps during synthesis can generate modifications in the alumina phases, in addition to the formation of aluminate species that are reduced during the catalytic activation step and modify the level of interaction between active and support phases. The catalytic activity test was performed with GHSV = 100 L g−1 h−1 and the formed carbon was quantified by thermogravimetric analysis. The Mn promoter exhibited the highest methane conversion rate during the initial stages of the reaction, in which the presence of MnO2 favored parallel reactions of methane decomposition. The phosphorus and cerium produced smaller amounts of coke, reducing the carbon generated due to the interaction of promoters with carbon on the surface of the catalytic sites. The Mg increases the interaction of the active phase with the support.

Investigations on structural, dielectric, and third-order nonlinear optical studies of Ni0.5Zn0.5Fe2O4 nanoparticles by microwave combustion method with different fuels (glycine, urea and citric acid)

In this article, Ni0.5Zn0.5Fe2O4 nanoparticles (NPs) were synthesized via microwave-assisted combustion method. XRD investigation indicates the cubic spinel structure. At ambient temperature, the dielectric constant and loss were determined by modulating the applied frequency (50 Hz to 200 kHz). The calculated third-order NLO susceptibility (χ(3)) was found for glycine (2.385 × 10-6esu), urea (0.9696 × 10-6esu) and citric acid (2.755 × 10-6esu). However, this work reveals that synthesized NPs have high convenience for optoelectronic, optical switching, and limiting applications.

Impact of green-synthesized Mg-doped Mn ferrite nanoparticles on light-driven degradation of dyes and their optoelectronic applications

Using Ocimum sanctum extract as fuel, magnesium-doped manganese ferrite nanoparticles with the chemical formula MgxMn1−xFe2O4, where x = 0.0–0.6, were synthesized using a green microwave-assisted combustion method.

Optimization of NiFe2O4 by different facile synthetic approaches and investigations on structural and electrochemical properties

Due to the metal ion's various oxidation states, ferrites, which are sustainable materials for energy conversion and storage as well as potential remedies to severe environmental problems, exhibit exceptional electrochemical properties. Nickel ferrite (NiFe2O4) has been synthesis by three different methods such as co-precipitation, sol–gel combustion and microwave-assisted combustion. The goal of this work is to investigate the link between morphology and electrochemical characterization. The XRD pattern confirmed the single-phase cubic spinel structure of prepared nanoparticles. The surface characteristics and elemental composition have been studied using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) with energy dispersive spectroscopy (EDS). The electrochemical properties of the prepared material as an electrode have been analyzed using a three-electrode setup in a 6 M KOH electrolyte solution. The higher calculated specific capacitance employed was 170.44 F/g at current density of 1 A g−1 and 237.84 F/g at 10 mV s-1 scan rare for the nickel ferrite made using a microwave-assisted combustion approach. Additionally, the chronopotentiometry for all ferrites showed a non-linearity curve, supporting the pseudo-capacitance behavior of the NiFe2O4 nanoparticles. The stability performance of NiFe2O4 (microwave-assisted combustion) was outstanding, and its specific capacitance retention is about 78 % after 5000 cycles.

Novel magnetic nanocomposites BiFeO3/Cu(BDC) for efficient dye removal

In this study, bismuth ferrite nanoparticles and metal-organic framework, Cu(BDC), were prepared by microwave-assisted combustion in solid state and ultrasound-assisted method, respectively. To enhance the properties of bismuth ferrite nanoparticles and Cu(BDC), we form them as their composite through microwave and ultrasonic probe strategies. Various analyses, including FT-IR, XRD, SEM, DRS, VSM, and so on, were applied to verify the synthesis accuracy. Then, the catalytic performances of the nanoparticles and the as-prepared nanocomposites were evaluated through photocatalytic degradation of methyl orange. Furthermore, the adsorption capacity of the as-synthesized materials was assessed toward the Congo red removal from wastewater. All the results prove that the proposed nanocomposite can be an acceptable candidate for eliminating contaminants from wastewater. The electrochemical properties of bismuth ferrite, BiFeO3/Cu(BDC) nanocomposite 1, and BiFeO3/Cu(BDC) nanocomposite 2 have been studied by cyclic voltammetry.

Exploring the role of fuel in the synthesis of bismuth ferrite nanoparticles by microwave-assisted combustion in solid state and the study of photocatalytic degradation of Brilliant Blue

The current research focused on the synthesis of bismuth ferrite nanoparticles using the method of microwave-assisted combustion in the solid state. The starting materials employed in the synthesis included bismuth nitrate pentahydrate, Bi(NO3)3·5H2O, and iron (III) nitrate nonahydrate, Fe(NO3)3·9H2O, with a 1:1 molar ratio and as an organic driving agent ammonium nitrate, (NH4) (NO3), along with various fuels such as glycine, urea, acetamide. The reaction conditions were optimized to achieve the desired BiFeO3 nanopowder, by using the molar ratio of glycine and ammonium nitrate as fuel and an irradiation power of 360 and 900 W for 20 min. Furthermore, the synthesized nanoparticles by 360 W were analyzed for their photocatalytic performance in the degradation of the organic dye Brilliant Blue as a pollutant.

Microstructure evolution of Ni-Cr-Mo superalloy fabricated by microwave-assisted combustion synthesis

In this study, the microwave-assisted self-propagation high-temperature synthesis (SHS) technique was utilized to successfully synthesize the Nistelle super C commercial alloy with the chemical composition of Ni59Cr23Mo18. The precursors used for this purpose were NiO, Cr2O3, and MoO3 oxide compounds. The thermodynamicall calculations were carried out by the Factsage software. The synthesized alloys' chemical composition, phase, and microstructure were evaluated by induction-coupled plasma, X-ray diffraction, optical microscopy, and scanning electron microscopy. The findings revealed considerable residual silicon in the final product due to using Si as the reducing agent. The presence of residual Si in the chemical composition led to forming a eutectic Niγ-FCC+ Mo2Ni3Si microstructure in the alloys produced by the alumino/silicothermic method. The high silicon content in the excess Al-containing sample led to forming of proeutectic Mo2Ni3Si phases with a petaloid morphology. Besides, this alloy displayed small islands of the interdendritic nickel silicide phase. Conversely, the aluminothermic sample showed a nearly single-phase structure with low amounts of the precipitates of chromium and molybdenum-rich phases. The phase diagram plotted for this sample indicated that the precipitates were probably TCP phases like σ and P. In all the samples, the segregation of Mo occurred significantly, while Cr was distributed almost uniformly in all regions. The formation of the Mo2Ni3Si intermetallic phase resulted in the significant segregation of Mo and depletion of the Niγ-FCC matrix from this element. However, the segregation of Mo was also observed near the grain boundaries in the single-phase sample. The results showed that the dissolution of the alloying elements, especially molybdenum, caused severe offset in some peaks of the Niγ-FCC XRD pattern.

Luminescence studies of high color purity red-emitting [formula omitted] phosphor prepared by microwave-assisted synthesis technique

A set of red-emitting phosphor materials (Ca1−xAl4O7:Eux3+, x = 0, 0.01, 0.03, 0.05, 0.07, 0.09, 0.11, 0.13) were synthesized through microwave-assisted combustion synthesis for the first time. The crystal structures and phase purity of Eu3+ ions-activated calcium dialuminate (CaAl4O7) phosphor were investigated by XRD study and Rietveld refinement analysis were performed. The prepared phosphors exhibit monoclinic crystal structure having C2/c space group. From the radius difference percentage calculation, the occupancy of Eu3+ ions in Ca2+ sites was confirmed which is in better harmony with the refinement result. Morphological analysis was investigated through SEM study. Structural characteristics and the presence of the functional groups were analysed though FTIR study. The optical band gap (Eg) was determined to be 5.46 eV by studying the UV–VIS reflectance spectra. PL measurements were carried out for the prepared material to study the luminescent behaviour. The presence of charge transfer band was observed in the excitation spectra. It is found that the prepared phosphor materials exhibits emission rich in red at 611 nm with fixed excitation wavelength at 393 nm. The concentration quenching and energy transfer kinetics were analysed by employing Blasse and Dexter’s formula that attributed the non-radiative energy transfer to the dipole-dipole (d-d) interactions. Local site symmetry was analysed to study the symmetry of the environment in the neighbourhood of Eu3+ ions in the host matrix. To analyse the colorimetric performance of the phosphor materials, the correlated color temperature (CCT), color purity were calculated by using the CIE chromaticity co-ordinates (CIE 1931). The calculated CCT value shows the appearance of the emitted color of the phosphor in the warmer region. CaAl4O7:Eu3+ phosphor manifests high color purity which was found to be 97.39 %. The PL decay time measurement were performed for Ca1−xAl4O7:Eux3+ (x = 0.07) phosphor to obtain the decay lifetime. The estimated decay time (1.44 ms) indicates that the prepared phosphor material has a good potency to be utilized as a red-emitting phosphor for wLED, display technology and other applications.

Effect of Mg doping on dielectric properties of ZnO nanoparticles synthesized by microwave-assisted combustion route

The primary aim of this research work is to study the dielectric properties of nanoscale ZnO and Mg-doped ZnO nanoparticles (NPs). The microwave-assisted combustion technique was used to synthesize ZnO and Mg-doped ZnO NPs (2, 4, and 6 atomic % of Mg). XRD (X-ray diffraction), FTIR (Fourier transform infrared) and SEM (Scanning electron microscope) methods were used to characterize the materials. From the XRD pattern, the phase confirmation and crystallite size of ZnO and Mg-doped ZnO NPs were estimated. The study of dielectric properties such as dielectric loss and permittivity, impedance and AC conductivity were observed in the range of frequency (1–106 Hz). The permittivity of ZnO and 6% Mg-doped ZnO showed an enhanced dielectric property than other doped materials at higher frequency. The additional mobile carriers added to the material as a result of raising the percentage of doping resulted in an increase in the material's dielectric loss. The hopping and tunnelling mechanism, which may be attributed to the migration of electrons into the conductive network formed by the crystallites of 6% Mg-doped ZnO and ZnO NPs, caused progressively increase in the values of AC conductivity of doped nanoparticles as the frequency range was increased. The impedance (real and imaginary) was decreased with increase in the amount of Mg (in terms of atomic %).