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Lithium-based ferrites having compositional formula Li0.35+y/2Zn0.1Mn0.1TiyFe2.35−3y/2O4 where y in the range of 0.00–0.75 with 0.15 step size were prepared by the solid-state route. The sample’s single-phase cubic spinel structure was discovered using XRD investigation. Additionally computed were the structural parameters such as density, porosity, crystallite size, and lattice constant. Energy dispersive X-ray was used to establish the sample’s elemental compositions while scanning electron microscopy was used to determine the sample’s microstructural information. The temperature response of d.c. resistivity (ρd.c.) behaviour was studied from temperature-dependent, transmission electron microscope was used to determine the particle size, shape and distribution. For these samples, the a.c. electrical conductivity (σa.c.) properties were also covered. The nyquist plot analysis revealed the conduction mechanisms and the semicircle curve obtained depicted the contribution of resistance from the ceramic samples. The report presents a systematic analysis and discussion of the acquired results. [ABSTRACT FROM AUTHOR]

Soft ferrimagnetic spinel lithium based oxides were prepared with additives like V2O5 and Na2SiO3 and sintered with the efficient microwave sintering technique. Tetravalent metal ions substituents like Mn+4, Ti+4 were used to enhance the important properties like D. C. resistivity, saturation magnetization, permeability, hysteresis and dielectric behavior. The ferrites were sintered at different sintering temperatures viz., 900, 950 and 1000 °C for 10 min by microwave technique and by conventional technique at 1050 °C for 4h. X-ray diffraction (XRD) studied the structural behavior which confirmed the spinel characteristics, Scanning electron microscopy (SEM) and EDAX revealed the microstructural and elemental compositions respectively of the ferrites. The use of additives and the microwave sintering significantly influencing the microstructural behavior and subsequently on the electromagnetic properties could be observed. Studies of initial permeability and initial permeability loss found to remain nearly constant with change in frequency until at certain frequency they showed resonance behavior. The resonance frequency's dependence on the microstructures of the ferrites could be observed. Temperature dependence behavior of the dielectric parameters and the B-H loop traced from torroidal samples of the ferrites were studied. [ABSTRACT FROM AUTHOR]

Rare earth yttrium substituted lithium ferrites Li0.5Zn0.1Ti0.1YxFe2.3–xO4 with nominal composition x = 0.00 to 0.10 in steps of 0.02 was prepared by the conventional ceramic method. The samples were sintered at 1050 °C for 6 h using resistive conventional heating. X-ray diffraction (XRD) patterns confirmed the formation of a single phase with a spinel structure. FTIR studies also confirmed the tetrahedral and octahedral metal-oxygen bonding of the spinel structure. Structural parameters like density, lattice constant, and crystallite size, site distances, bond length distances were measured from XRD data. The crystallite size reduces while the density increased with the progressive substitution of Y3+ ions. The Fe3+ ions at the A and the B sites mainly contributes to the electromagnetic properties of ferrites. Y3+ ions preferably entering the B sites can significantly interfere with the conduction mechanism of lithium ferrites. The objective of the present work is to find out the effect of Y3+ substitution on the structural and electrical conduction response Li-Zn-Ti ferrites. The DC resistivity initially is found to increase for concentration x = 0.04 and then decrease with further substitution. The study of the temperature dependence of DC resistivity depicts two types of conduction mechanisms in the range studied. The results obtained are analyzed and presented in the paper. [ABSTRACT FROM AUTHOR]

Potassium sodium niobate (KNN) is an environmentally compatible piezoelectric material for substituting harmful lead-based ceramics. KNN-based ceramics have excellent piezoelectric properties with high Curie temperature. But, KNN faces difficulties during the processing like volatilization of alkali elements, chemical inhomogeneity, low densification, etc. The objective of this research is to investigate the impact of certain metal oxides additions like ZnO and MnO2 as sintering aids to solve the problems of the preparation and hence study the structural and electric properties of K0.5N0.5NbO3 (KNN) ceramics. ZnO and MnO2 added potassium sodium niobate, K0.5N0.5NbO3 was prepared by using the ceramic method. The prepared samples were sintered at 1000 °C for 2h conventionally. The structural properties of the ceramics have been analyzed by using X-Ray Diffractometer. The study demonstrates the formation of the orthorhombic-symmetric perovskite phase in all the prepared samples. The microstructural behavior of the ceramics has been characterized by techniques such as scanning electron microscopy (SEM) and compositional properties were studied by energy dispersive x-ray (EDAX). The effects of metal oxide additions on the electronic properties such as dielectric constant, dielectric loss, impedance properties, Nyquist plot, etc., were studied. The results have been analyzed and discussed in the paper. [ABSTRACT FROM AUTHOR]

Lead-free K0.47Na0.47Li0.06NbO3 added with different oxides such as ZnO, Na2SiO3, Bi2O3, NiO, and CoO were prepared with conventional two steps sintering ceramic method where the samples were sintered at 1050 °C(5 min) and 950 °C(4h). The phase structures and crystallite sizes were studied using X-ray diffraction analysis. A dispersive behavior is observed when dielectric constant and dielectric loss were studied with variation in frequency in the range from 20 Hz to 5 MHz at room temperature. It is seen that addition of oxides improved the dielectric properties. The a. c. conductivity and impedance characteristics for the samples were also measured for a wide range of frequencies using an impedance analyzer. The Nyquist impedance plot for these samples studied for the conduction mechanism. The results were analyzed and presented in the paper. [ABSTRACT FROM AUTHOR]

Tetravalent titanium substituted lithium zinc manganese ferrite having chemical formula Li0.35+x/2Zn0.1Mn0.1TixFe2.35 − 3x/2O4 where x = 0.00, 0.15, 0.30, 0.45, 0.60, 0.75 were prepared by using the solid-state ceramic technique. Using additives V2O5 and Na2SiO3 as sintering aids, the samples were calcined and sintered at 900 °C and 950 °C, respectively for 1 h each, at a regulated heating rate of 10 °C/min. The X-ray diffraction (XRD) studies showed a single-phase spinel structure. XRD data were used to assess the structural information including density, lattice constant, and crystallite size. The additives reduced the sintering temperature and time and an increase in porosity has been observed with the increase of Ti4+ substitution. Scanning electron microscopy (SEM) was used to analyze the samples' microstructure, while Energy-dispersive X-ray (EDAX) analysis was used to identify the different elemental makeup. The fluctuation of the initial permeability and permeability loss at room temperature with a change in frequency was investigated using an impedance analyzer and found that higher substitution reduced the resonance frequency. The magnetic hysteresis studies showed that saturation magnetization reduced with an increase of Ti4+ substitution. The results obtained were analyzed and discussed systematically in the paper. [ABSTRACT FROM AUTHOR]

MnO2 added potassium sodium niobate (KNN) electroceramics were prepared by conventional double sintering ceramic route. The samples prepared have the compositional formula K0.5Na0.5NbO3+ (x)MnO2 where x = 0 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt% and 25 wt% is the amount of MnO2 added. The sintering of the samples was done using the microwave sintering technique. Pre-sintering was done at 850 °C for 20 min. Different sintering conditions may results in KNNs with varied properties. The studies of the structural properties of the prepared samples were done by X-ray diffraction (XRD) technique. It has been found that addition of MnO2 to KNNs and sintering at 1000 °C for 20 min and at 1050 °C for 10 min showed all the KNNs crystallization in tetragonal phase with nearly similar structural parameters. The electrical properties such as dielectric constant, dielectric loss and ac conductivity of the prepared samples were investigated using an impedance analyzer. The room temperature frequency variation of electrical properties showed a dispersive behavior for all the samples. The temperature variation of the dielectric properties showed an increase with the increase of temperature. The results of the various measurements are discussed in the paper. [ABSTRACT FROM AUTHOR]

Different types of ferrimagnetic spinel nanoferrites having the general formula Li0.5Fe2.5O4, NiFe2O4, ZnFe2O4 and MnFe2O4 were synthesized by chemical sol-gel method. The synthesized nanoferrites were milled using high energy ball milling to get fine and homogenous nanoferrite particles. The nanoferrites were characterized using X Ray Diffraction (XRD) Technique and Fourier Transform Infrared (FTIR) Spectroscopy. XRD patterns confirmed the spinel structure of the samples. FTIR studies show the metal oxygen bond of the tetrahedral and octahedral sites. These nanoferrite particles were used to prepare ferrite nanofluids using different solvents. The optical property of these fluids was studied using a UV spectroscopy. The results of all the measurements were analyzed and reported in this paper. [ABSTRACT FROM AUTHOR]