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M-type Hexa-ferrites powders of chemical composition Ba 0.5 Sr 0.1 Zn 0.4 Fe 12 O 19 was prepared by the use of the co-precipitation technique. The heat treatment of this ferrite composition was done at various temperatures (700, 800, 900, 1000, 1100, and 1200 °C) for 6 h. The X-ray diffraction (XRD) analysis of all the prepared powder samples confirmed the emergence of a hexagonal structure. The high-intensity peaks of the samples were indexed and showed a single phase. The size of crystallite was obtained within the range of 21–42 nm. The surface morphology was carried out with a Scanning electron microscope (SEM). The grain size showed the hexagonal shape, and average grain sizes were in the range of ~ 211 nm. Spectral information was found using the Fourier transform infrared (FTIR) spectroscopy to confirm the phase of M-type hexaferrite. The dielectric parameters were measured within the high-frequency range of 5 MHz - 3 GHz. The dielectric constant was increased with an increase in temperature. The dielectric studies were found by the establishment of space charge polarization as per the two-layer model provided by Maxwell-Wagner and the study of phenomena of Koop's theory. The magnetic characteristics including coercivity (HcB) and retentivity (Br) were measured from BH/JH hysteresis loops. The enhancement of coercivity was observed from 1.23 × 10+3 Oe to 1.50 × 10+3 Oe, while the retentivity increased from 1.334 × 10+3 G to 1.598 × 10+3 G with an increase in temperature. Outstanding properties of synthesized materials suggested their use in large-frequency applications, including recording media and permanent magnets. [ABSTRACT FROM AUTHOR]

The LiAlSiO 4 :Ce3+ (0–11 mol%) nanocomposites are synthesized by low temperature solution combustion method using aloe vera gel as a fuel. The prepared samples are characterized by powder X-ray diffraction (XRD) to know the crystallite size, optical energy band gap by Kubelka-Munk (K-M) plot and surface morphology by scanning electron microscope (SEM) coupled with energy dispersive X-ray (EDX) analysis for elemental confirmation. The stretching frequency of all nanocomposites is confirmed by Fourier transform infrared (FTIR) spectra. The Raman spectroscopy provides a structural fingerprint by which molecules can be identified. The current-voltage (I–V) characteristics showed that the prepared samples obey Ohm's law. DC conductivity is studied for temperature ranging from 30 - 450 οC and activation energy is calculated by Arrhenius plot. Further, the present method was reliable, environmental friendly and alternative to economical routes. [ABSTRACT FROM AUTHOR]