Electrical Conductivity Studies Research Articles

Theoretical study of glycoluril by highly symmetrical magnesium oxide Mg12O12 nanostructure: adsorption, detection, SERS enhancement, and electrical conductivity study.

Using metal substrates that are nanoscale in size, surface-enhanced Raman scattering (SERS) is a technique for enhancing the Raman signal of biomolecules. Numerous industries including sensing materials, adsorption and medical devices, use nanomaterials like nanocages and nanoclusters. To discover a possible novel sensor platform involving a small metal cluster and a curved rigid substrate, we used density functional theoretical (DFT) simulations to explore the adsorption of glycoluril (GLC), a prospective drug intermediate, on a pure magnesium oxide cage (Mg12O12). This well defined cage was used as (i) an exact probable structure that could be used as well as (ii) a general model for MgO nanostructures. We also investigated the mono Al-doped Mg12O12 nanocage version Mg11AlO12. All computations were performed at the M06-2X level of theory. The GLC binds to the Mg12O12 nanocage by way of strong donor-acceptor interactions. The adsorption is releasing - 45.80kcalmol-1 of energy. Due to Al doping, the energy gap of GLC-Mg11AlO12 (1.91eV) is reduced from that of GLC-Mg12O12 (4.28eV) and hence there is an increase in electrical conductivity of GLC-Mg11AlO12. The electronic change in the nanocage's conductivity can be transformed into an electrical signal which can be used to detect the presence of the drug analyte. In addition, when a GLC molecule is present, the work function of the nanocage is also reduced. The MgO nanocage, we conclude, is a work function type as well as a possible electronic sensor for GLC drug detection. GLC desorption from the Mg11AlO12 surface recovers more quickly in comparison with Mg12O12 recovery time. The AIM and NCIs assessed in this study were performed to help analyze the electronic structures of the complexes. Our findings pave the possibility for Mg11AlO12 nanostructures to be used in drug recognition.

Electrical conductivity and thermodynamic studies on Sodium Dimethyldithiocarbamate in non aqueous solvents Dimethylformamide (DMF), at different temperatures

This paper threw some light on the behavior of Sodium N,N-Dimethyldithiocarbamate as an electrolyte. The effect of solvents on the conductance of this salt would be discussed via measurements of Λo, ao and KA, since it can be assumed that the different solvents have a little chance to impose great variations on the solvation processes. The conductance method was chosen as a tool to illustrate the electrolyte-solvent interactions. Fuoss–Onsager equation would be tested using Sodium Dimethyldithiocarbamate in presence of dimethylformamide solvent at different temperatures. The conductance of dilute solutions of Sodium N,N-Dimethyldithiocarbamate is measured in Dimethylformamide, at different temperatures (25, 30, 35 and 40 °C). Accurate values of Λo were obtained by applying the (Fuoss–Kraus–Shedlovsky) equation. Finally, the (Fuoss–Onsager) equation was solved to give the correct values of the constants Λo, J, KA and a° (the closest distance of approach) for Sodium N,N-Dimethyldithiocarbamate salt in Dimethylformamide solvent. Λo and a° (solvation) increase with increasing temperatures. Thermodynamic parameters (∆G°, ∆H°, ∆S° and ∆Es) of Sodium N,N-Dimethyldithiocarbamate in Dimethylformamide were calculated from conductance measurements, the activation energy (∆Es), the enthalpy change (heat of association) (∆H°) and the entropy change (∆S°) are positive, however The free energy change (∆G°) values was negative for Sodium N,N-Dimethyl dithiocarbamate in DMF systems studied with increasing the temperature.

Preparation and Characterization of Al-Cu-Al2O3/Gr Nano Compound by Metallic Powder Method and Study of the Effect of the Rolling Process on Physical Properties as Suitable Materials for Heat Sink

Al-Cu-Al2O3 / Gr Nano compound was successfully prepared by metallic powder method, 6 samples were prepared with different weight ratios of graphene, 10% copper and 2.5% Al2O3 and proportions of 0.5, 1, and 1.5 graphene were prepared, the samples were run in a mill from Ceramic in a ratio of 1:5 powder into balls for 35 hours, which helped to break the aluminum and copper particles and reduce their size, which helps in the process of homogeneous mixing of the compound. The samples were compressed at 60 bar pressure and sintered in a vacuum at 550 and 565 degrees Celsius for 60 minutes. Sintering at 550°C proved to be more suitable for the mixture. Two identical sets of samples were prepared. Both SEM were used to investigate the microstructure and components of the sintered nanocomposites. Relative density, hardness, electrical conductivity and thermal conductivity study. The rolling process of the samples was carried out with a percentage of 35% of the sample size successfully at a temperature of 480 degrees Celsius, and this led to an improvement in the density of the samples and hardness and an increase in the diffusion of the reinforces, which led to an improvement in electrical conductivity by 16: 25% and a better improvement in thermal conductivity. Improved up to 1.5% graphene by weight after rolling and 1% graphene before rolling.

Synthesis and characterization of new multiferroic (BiBa)(FeTi2)O8

The present communication reports the study of various properties (i.e., structural, electrical, dielectric, ferroelectric, and magnetic) of new multiferroic: (BiBa)(FeTi2)O8 synthesized by a mixed oxide reaction route. The analysis of the X-ray diffraction profile at room temperature ensures its phase formation in the orthorhombic crystal structure. The micrographic study divulges irregular shape grains (mostly rectangular) with an average grain size of 3.5 μm. The compositional study displays the desired stoichiometry. The study of electrical (impedance, modulus, and conductivity) and dielectric properties (dielectric constant and tangent loss) of the sample at different temperatures (RT – 773 K) and electric field frequency (1 kHz-1MHz) provides many new experimental data, and insight mechanisms. The temperature dependence of the dielectric constant exhibits a dielectric anomaly around 523 K that may be due to the combined effect of oxygen vacancy mediated redox reaction (Fe3+→Fe2+ and Ti4+→Ti3+) and Maxwell-Wagner polarization. The loss tangent follows a similar trend to that of the dielectric constant except for an additional low-frequency relaxation peak of about 543 K. The dielectric loss tangent exhibits low value in low temperature and high-frequency regions, indicating that the sample can be a potential candidate for data storage devices. The ferroelectric recording shows a non-linear PE loop at room temperature. The room temperature magnetic recordings show evidence of weak ferromagnetism due to suppression of spiral spin structure as opposed to the antiferromagnetic nature of BiFeO3. The coexistence of these unique features enables the synthesized sample to be used in voltage-controlled data storage devices.

The Os substitution into Fe sites in LuFeO3 multiferroic and its effects on the electrical and dielectric features

Solid-state technique was utilized to obtain the LuFeO 3 (LFO) and LuFe 1−x Os x O 3 (LFOO) compounds having x = 0.05 and 0.10. The orthorhombic structure and the presence of secondary phases in the studied samples have been unveiled by X-ray diffractometer (XRD) investigations. The scanning electron microscope (SEM) examinations have unveiled that not only the particle sizes enlarge with Os substitution but also particle agglomeration takes place. The X-ray photoelectron spectroscopy (XPS) investigations have exposed the oxidations of Fe as 2 + and 3 + for the LFO sample, 3 + for 5 mol% Os substituted specimen and mix of 2 + and 3 + for 10 mol% Os doped sample. In addition, it was shown that Os has 4 + oxidation state in the doped samples. Dielectrical and electrical conductivity studies of the obtained ceramics conducted between − 100 °C (173 K) up to 100 °C (373 K) with 20 °C temperature pace have shown that the undoped sample has much higher values than the Os doped samples. Such differences have been ascribed to the absence of Fe 2+ ions and lattice distortions in the Os doped samples. In addition, it was realized that different conduction models need to be adapted to comprehend the conduction mechanism in the examined specimens. • LuFeO 3 (LFO) and Os doped LFO were synthesized by solid-state reaction. • Os substitution lowers the ratio of Fe 2+ ions in LFO structure. • LFO and Os doped LFO have multiple relaxations. • Dielectric constant and electrical conductivity were deteriorated after Os substitution. • Conduction mechanism can be comprehended by multiple models depending upon frequency and temperature.

An Electroconductive, Thermosensitive, and Injectable Chitosan/Pluronic/Gold-Decorated Cellulose Nanofiber Hydrogel as an Efficient Carrier for Regeneration of Cardiac Tissue.

Myocardial infarction is a major cause of death worldwide and remains a social and healthcare burden. Injectable hydrogels with the ability to locally deliver drugs or cells to the damaged area can revolutionize the treatment of heart diseases. Herein, we formulate a thermo-responsive and injectable hydrogel based on conjugated chitosan/poloxamers for cardiac repair. To tailor the mechanical properties and electrical signal transmission, gold nanoparticles (AuNPs) with an average diameter of 50 nm were physically bonded to oxidized bacterial nanocellulose fibers (OBC) and added to the thermosensitive hydrogel at the ratio of 1% w/v. The prepared hydrogels have a porous structure with open pore channels in the range of 50–200 µm. Shear rate sweep measurements demonstrate a reversible phase transition from sol to gel with increasing temperature and a gelation time of 5 min. The hydrogels show a shear-thinning behavior with a shear modulus ranging from 1 to 12 kPa dependent on gold concentration. Electrical conductivity studies reveal that the conductance of the polymer matrix is 6 × 10−2 S/m at 75 mM Au. In vitro cytocompatibility assays by H9C2 cells show high biocompatibility (cell viability of >90% after 72 h incubation) with good cell adhesion. In conclusion, the developed nanocomposite hydrogel has great potential for use as an injectable biomaterial for cardiac tissue regeneration.

Study of high-temperature electrical conductivity and thermoelectric performance in Mg2−δSi0.35−xSn0.65Gex (δ = 0–0.04 and x = 0, 0.05) intermetallic alloys

Study of high-temperature electrical conductivity and thermoelectric performance in Mg2−δSi0.35−xSn0.65Gex (δ = 0–0.04 and x = 0, 0.05) intermetallic alloys

Synthesis and characterization of new compounds of amic acids derived from cephalosporins, the study of some physical applications and evaluation of their biological activity

In this research, amino acids were prepared from the reaction of cephalosporins with anhydrous acids, and the accuracy of the prepared compositions was confirmed by measuring their physical properties, including melting point, molecular weight and colour, as well as through spectroscopic measurements, including Uv, FTIR, 1H-NMR, 13C-NMR, mass spectrometry, (S.E.M.), (C.H.N.). A study of electrical conductivity and a survey of the biological activity of some prepared compounds and on four types of pathogenic bacteria, two of which are Gram-positive, and two are Gram-negative. They are each of (Staphylococcus aureus, Enterococcus faecalis, Klebsiella pneumonia, and Pseudomonas putida). The use of Acker-Hinton's type of culture medium (Molar Hunting Agar) and aqueous solutions of the two compounds [DM7] were also prepared. [DM3] and in concentrations (0.01,0.001,0. 0001,0.00001) mg/ml and by using a solvent dimethyl sulfoxide (DMSO), a sensitivity test was conducted for the bacteria isolates that were used in the study by diffusion method, and using the antibiotics Cefixime, Ceftriaxone, Ampicillin as a control sample.

Synthesis of x[La0.67Sr0.33MnO3] – (1-x)[0.5Ba0.7Ca0.3TiO3-0.5BaZr0.2Ti0.8O3] multiferroic composite with its dielectric, magnetodielectric, magnetic and electrical conductivity studies

The present paper studies the synthesis and characterization of x[La0.67Sr0.33MnO3] – (1-x)[0.5Ba0.7Ca0.3TiO3-0.5BaZr0.2Ti0.8O3] multiferroic composite for x = 0.1 and 0.175. Parent materials of ferroelectrics Ba0.7Ca0.3TiO3 (BCT) and BaZr0.2Ti0.8O3 (BZT) and ferrite La0.67Sr0.33MnO3 (LSMO) have been prepared via hydroxide co-precipitation method while its composite x[LSMO] – (1-x)[0.5 BCT -0.5 BZT] was synthesized by ceramic route. The presence of ferroelectric and ferrite phases were confirmed by structural studies of composites. Microstructure shows the dense and closely packed LSMO particles over BCT-BZT ferroelectric phase. The dielectric properties of composites were studied in frequency range of 1KHz-1MHz and from room temperature to 500OC. P-E hysteresis loops of composites shows noticeable values of saturation polarization (Ps) and remnant polarization (Pr). Significant value of magnetoelectric (ME) coupling coefficient (α) of 2.15mV/cmOe was observed for the composite 0.175LSMO – 0.825(0.5BCT-0.5BZT) at 1 KHz frequency. Magnetodielectric (MD) properties of the composites were investigated by measuring the magnetocapacitance up to 1 T magnetic field. MD effect can be explained on the basis of contribution of dielectric constant due to interfacial polarization which depends on magnetic field and changes due to induced stress. Frequency dependent ac conductivity was confirmed by Jonscher's Universal Power law. Temperature dependent dc conductivity of the materials shows the Arrhenius behavior. As the ferrite content of LSMO increases in the composite saturation magnetization increases which can be studied by the hysteresis plot.

Extensive Analysis on the Thermoelectric Properties of Aqueous Zn-Doped Nickel Ferrite Nanofluids for Magnetically Tuned Thermoelectric Applications.

Because of the ever-increasing consumption of energy, higher-efficiency thermoelectric materials are in more demand. In this regard, initially, ZnxNi(1-x)Fe2O4 nanoparticles were synthesized using a co-precipitation technique and investigated using Rietveld refinement and Brunauer-Emmett-Teller (BET) analyses. Then, they were dispersed in water to obtain stable 1 vol % of aqueous ZnxNi(1-x)Fe2O4 nanofluids and their viscous, electrical, thermal, and thermoelectric properties were analyzed in the absence and presence of a magnetic field. The Rietveld refinement revealed the formation of single phase spinel ferrite structures and cationic distribution of ZnxNi(1-x)Fe2O4 nanoparticles, whereas BET analysis revealed the surface area of the nanoparticles. The viscosity studies proved the pseudo-plastic shear thinning behavior and dipole-dipole interactions of ZnxNi(1-x)Fe2O4 nanofluids. The electrical conductivity, thermal conductivity, and Seebeck coefficient studies revealed that the maximum enhancement was observed for the Zn0.2Ni0.8Fe2O4 nanofluid, which was attributed to the enhanced electrical double layer formation and Brownian motion of nanoparticles in the nanofluid. The enhancement in the properties of synthesized nanofluids in the presence of a magnetic field was attributed to the formation of chain-like structures, which was substantiated through the magneto-viscosity studies. The thermoelectric energy conversion efficiency of ZnxNi(1-x)Fe2O4 nanofluids was calculated which showed that the maximum enhancement of 27% was observed in the Zn0.2Ni0.8Fe2O4 nanofluid at 770 G. The observed results proved that the synthesized nanofluids are magnetically tunable thermoelectric materials which are suitable for waste heat energy harvesting applications.

Preparation and Characterization of PANI/PVA Blends as Electrolyte Materials

This work presents a detailed study on the preparation and performance of polyaniline (PANI)/Polyvinyl alcohol (PVA) blend. The blends are prepared by the casting method at different weight ratios (1, 2, 3, 4, and 5 wt%). The structural morphology was characterized using scanning electron microscope SEM. The morphological analysis showed a uniform blend of PANI with PVA matrix. PVA exhibits lamellae structure of different shapes and dimensions. For 1% PANI, the results showed homogeneous blending, which decreases with an increase of the PANI ratio. Phase separation and semispherical region formation in the PVA matrix were seen. It was found that incompatibilities increase with increasing the PANI ratio. Also, the results proved in the blends scanning electron microscope anilinium cation – radical surfaces for an aggregate of different dimension and spherical shapes, which induced by surface tension. The electrical conductivity study of PANI/PVA blends and PVA reveals that PANI/PVA gives the conductivity of 10−4(cm.Ω)-1, while PVA presented the lowest conductivity with the value of 10−12 (cm.Ω)-1. The results also showed an increase in ionic conductivity with temperature and PANI weight ratio. The increase in electrical conduction with increasing temperatures is due to the negative thermal coefficient, this result is attributed to the polymer chains that act as traps for charge carriers, and when the temperature rises, the transfer mechanism will be reigned by the hopping process.

Structural, Optical and Electrical Conductivity Studies in Polycarbazole and its Metal Oxide Nano Composites

Polycarbazole (PCz) has been synthesized by chemical oxidation method using APS as an oxidizing agent and PCz/CuO and PCz/Fe2O3 nanocomposites by in situ polymerization method for different wt% of CuO and Fe2O3 at room temperature. XRD patterns confirmed crystalline nature of samples. FTIR indicated strong interaction between PCz and nano fillers. The morphological and optical absorption studies were carried out using SEM and UV–Vis respectively. Addition of CuO or Fe2O3 to PCz decreased its direct and indirect band gaps. However, band gap showed a small change with dopant contents up to 30%. Urbach energy decreased with the addition of dopants. But Urbach energy of the composites increased with increasing dopants content from 10 to 30%. DC conductivity of PCz and its nanocomposites has been measured by following two probe technique in the temperature range 300–423 K. The conductivity of both the nanocomposites is found to be less than the pure PCz and it is found to increase with wt% of CuO or Fe2O3 as the case may be. The activation energy has been determined by fitting Arrhenius expression to the dc conductivity data at high temperature. The activation energy of polycarbazole is determined to be less than that of the composites. In both the composites, activation energy decreased and conductivity increased with the increase of dopant content.

Electrical conductivity studies on LAMOX based electrolyte materials for solid oxide fuel cells

In this study, the electrical conductivity of the LAMOX based electrolytes (La1.8Dy0.2Mo2-xWxO9 (x = 0, 0.1, 0.2, 0.5, and 1), and La1.8Dy0.2Mo2-xGaxO9 (x = 0.1)) synthesized by the citrate complexion method has been studied using DC four-probe method. The electrical conductivity of the electrolytes is measured in the temperature range of 800–400 °C in the air (∼100 ml min−1). The effect of W and Ga substitution at the Mo site on the electrical conductivity is evaluated. The long-term electrical conductivity stability test (time on stream) (5 h) is conducted at 650, 580, and 520 °C to study the effect of possible phase transition on electrical conductivity. A high-temperature XRD study is also conducted in the temperature range of 500–650 °C (during heating and cooling) on selected electrolyte materials (La1.8Dy0.2Mo2-xWxO9 (x = 0 and 0.1) and La1.8Dy0.2Mo2-xGaxO9 (x = 0.1)) to study the α↔β phase transition. The electrical conductivity of these electrolytes in the air at 800 °C is in the range of 5.3 × 10−2 – 14 × 10−2 S cm−1. The activation energy (EA) of these electrolytes is in the range of 1.11–1.62 eV. The VTF parameters σo, B, and To are in the range of 67.46–395.88 S cm−1 K0.5, 0.122–0.254 eV, and 247–347 °C, respectively. The La1.8Dy0.2Mo2-xWxO9 (x = 0.1) shows highest electrical conductivity (14 × 10−2 S cm−1, EA = 1.54 eV) among all electrolytes in air at 800 °C and for this material the VTF parameters σo, B, and To are 170.32 S cm−1 K0.5, 0.153 eV, and 302 °C, respectively.

Chelate Formation between Thorium(IV) and p-Nitrobeazeneazochromotropic Acid (Chromotrope 2B) : Spectrophotometric and Electrical Conductance Studies

Chelate Formation between Thorium(IV) and p-Nitrobeazeneazochromotropic Acid (Chromotrope 2B) : Spectrophotometric and Electrical Conductance Studies

Study the structural and electrical properties of prepared PANI/TiO2 nanocomposites for electronic devices

Structural and electrical properties of pure Polyaniline (PANI), that doped with dodecyl benzene sulfonic acid (DBSA) and nanocomposite films Synthesized by insitu chemical polymerization method in the presence of TiO2 nanoparticles. All the prepared samples have been investigated by x-ray diffraction (XRD), fuorier transformation infra-red (FTIR), and electrical conductivity studies. The results noticeably establish that the composites films have good crystallinity increase with increasing the TiO2 content in the polymer matrix. Also, there are physiochemical interactions between PANI and TiO2 nanoparticles that revealed by FTIR tests.

Influence of V2O5 concentration on structural and electrical transport properties of semiconducting ternary glass and glass-ceramics nanocomposite system

The effects of V2O5 concentration on semiconducting xV2O5–(1-x) (0.25Nd2O3–0.75ZnO) glass nanocomposites were investigated by structural, optical, and electrical conductivity studies. The composition dependency of physical attributes like density, molar volume, bond dissociation energy, number of bonds per unit volume, etc., was established. Using X-ray diffraction and field-emission scanning electron microscopy, we identified the presence of different nanocrystallites and amorphousness. DC electrical conductivity was caused by the small polaron hopping due to the presence of V4+ and V5+ valence states, enhanced as the small polaron radius was reduced with rising V2O5 concentration. The non-overlapping small polaron tunnelling (NSPT) model was the preferred AC conduction process, and reducing nature of tunnelling distance enhanced AC conductivity with increasing V2O5 concentration. We modified the existing NSPT model to get reasonable values for fitting parameters. The scaled AC conductivity spectra revealed temperature independence and the composition-dependent conductivity relaxation process of small polarons.

Appraisal of non-destructive in situ techniques to determine moisture- and salt crystallization-induced damage in dolostones

The characterisation of both surface and subsurface pathologies (position, depth, width, …) that affects the porous materials used in building constructions, once in service, is important to establish the most suitable intervention strategy. In this sense, the use of non-destructive techniques allows the analysis of different properties without affecting the material. The present study shows the accuracy of different non-destructive in situ techniques, such as: electrical conductivity and capacitance, infrared thermography, ultrasonic pulse velocity, sound absorption, and electrical resistivity tomography, applied on dolostone ashlar stones outer façade of a sixteenth-century belltower, affected by moisture and salt induced decay. The joint analysis of the results obtained with different techniques substantially improves the interpretation and characterisation of the detected pathologies, as they complement each other perfectly. Electrical resistivity tomography, which delivers resistivity cross-sections, yields very good results in detecting subsurface pathologies, and sound absorption is particularly useful for stone surfaces. In both cases, the frequency of the electric field and that of the acoustic emission to detect the extent of damage must be established in advance. The joint study of electrical conductivity and capacitance determines the degree of moisture/salts, both at the surface and subsurface, in the materials tested, one of the main causes of scaling and flaking in stony materials. However, the petrological characteristics of the materials used and the identification of the saline phases present must be known in advance to make a correct interpretation of the results.

Mononuclear pyrazine-2-carbohydrazone metal complexes: Synthesis, structural assessment, thermal, biological, and electrical conductivity studies

Mononuclear complexes of VO(IV), Cr(III), Fe(III), MoO2(VI), WO2(VI), and UO2(VI) with pyrazinecarbohydrazone ligand (N'-(1-(5-chloro-2-hydroxyphenyl)ethylidene)pyrazine-2-carbohydrazide) were synthesized and the prepared complexes were characterized by elemental analysis, magnetic susceptibility, powder X-ray analysis, various spectroscopic techniques (IR, 1H NMR, 13C NMR, and Mass spectra), SEM, and thermal analysis. VO(IV) complex was additionally characterized by ESR study. The ligand behaves as a dibasic tridentate, coordinating through the phenolate oxygen, azomethine nitrogen, and enolate oxygen atoms towards the central metal ion. The analytical data suggest 1:1 metal to ligand stoichiometry for all complexes. The physicochemical data suggested octahedral geometry to Cr(III), Fe(III), MoO2(VI), WO2(VI), and UO2(VI) complexes while square pyramidal to VO(IV) complex. The SEM analysis indicated the presence of well-defined crystals free from any shadow of the metal ion on their external surface with particle sizes of greater than 10 μm. Various kinetics and thermodynamic parameters are calculated using Coats-Redfern method and on the basis of half decomposition temperature the thermal stability order of complexes was found to be Cr(III) < WO2(VI) < Fe(III) < MoO2(VI) < VO(IV) < UO2(VI). The solid-state electrical conductivity of compounds was measured in their pellet form in the temperature range form 313-373 K. The conductivity data vary exponentially with the absolute temperature and obey Arrhenius equation indicating their semiconducting behavior. The antibacterial as well as antifungal activities of ligand and its metal complexes were evaluated in vitro against Gram positive bacteria (S. aureus and B. subtilis) and Gram-negative bacteria (E. coli and S. typhi.) and fungal strains (C. albicans and A. niger). The activity data revealed metal complexes are found to be more active than the ligand.

Optical, Electrical and Structural Characterization of MNA Doped PS: PVS Polyblends Thin Film

PS: PVC polyblend thin films doped with various concentration of Meta nitro aniline (MNA) (0.01 %, 0.05 %, 0.1 %, 0.5 %, 1 %, and 5 %) were synthesized by using the method of solution evaporation technique. The amorphous nature of doped thin film samples was confirmed by the X – Ray diffraction pattern which shows the decrease in intensity with the increase in the concentration of dopant. UV - vis spectra show increase in the absorption band with the increase percentage of dopant.The electrical conductivity study shows that the doping of MNA into the PS: PVC polymer blend thin film enhances its ionic conductivity with increase in temperature. This improved properties in the doped polyblend thin films are due to the increase in mobility of charge carriers.

Study of XRD, dielectric properties and DC electrical conductivity of Li-Zn-Al ferrite synthesized by sol–gel combustion method

A series of nanocrystalline aluminum (Al3+) doped Lithium-Zinc ferrites (LZA) having general chemical formula Li0.5(1- x )Zn x Fe2.5- y Al y -0.5 x O4 with x = 0.1 and y = 0.2 (S1C1), 0.4 (S1C2), 0.6 (S1C3) and 0.8 (S1C4) were synthesized by citrate sol-gel combustion method. The structural characterizations of the samples were carried out by X-Ray Diffraction (XRD) studies. Morphological investigations were performed using Scanning Electron and Transmission Electron Microscopies. XRD analysis confirmed the formation of single phase of the reported samples. All the samples crystallized in spinel cubic crystal structure with Fd-3m (227) space group. Crystallite size was estimated in the range of 19 nm to 21 nm using Scherrer formula. The variation of D.C. electrical conductivity as a function of temperature of as-prepared samples revealed the semiconducting nature. The dielectric constant (ε'), dielectric loss factor (ε") and the dielectric loss tangent (tan δ) were studied in the frequency range of 1 KHz to 1 MHz at room temperature by using LCR Meter. The values of dielectric constant, dielectric loss factor and dielectric loss tangent were found to decrease with addition of Al3+ content as well as with the increase in the frequency. The observed dielectric dispersion at lower frequency is attributed to Maxwell-Wagner type of interfacial polarization due to hopping of charge between Fe+2 and Fe+3. High value of resistivity (≈106 Ω-cm) and low value of dielectric constant and dielectric loss are the prime achievements of the present research work which make these investigated nanoferrites useful for the microwave devices.