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The Impact of Co and Gd on the structural, magnetic and dielectric properties of ZnO nanotubes synthesized by co-precipitation is reported. The results demonstrate that incorporating Co and Gd into ZnO diminished crystallinity while retaining the optimum orientation. The outcomes of transmission electron microscopy and scanning electron microscopy examined that the Co and Gd dopants had no effect on the morphology of the produced nanotubes. It was also discovered that as the frequency and concentration of Gd co-dopant decreased, the dielectric constant and loss values increased. When doping was present, the dielectric constant and ac electrical conductivity response was found to be inversely related. Ultimately, at 300K, Co and Gd co-doped ZnO nanotubes exhibited ferromagnetic properties. When Gd doping was increased to 3%, the ferromagnetic response increased. Since then, increasing the Gd co-doping, the ferromagnetic response decreased. For the same sample (Zn0.96−xCo0.04Gd0.03O nanotubes), the electrical conductivity exhibited also superior to pure and low Gd doped ZnO. Its high ferromagnetism is usually caused by magnetic impurities replaced on the ZnO side. Therefore, considering the behaviour of these nanotubes, it can be sued spin-based electronics. [ABSTRACT FROM AUTHOR]

Perovskite type Ba1−xSrxZr0.2Ti0.8O3 (with x = 0.0, 0.1, 0.2 and 0.3) ceramics have been synthesized through conventional two-step solid-state reaction method. The structural characterization was done using an X-ray diffraction study. All the compositions reveal a single-phase cubic structure. The dielectric measurements were taken at various temperatures (100 to 300 K) and various frequencies (1 to 500 kHz) for all the prepared compositions. This study reveals that the Ba1−xSrxTi0.8Zr0.2O3 (with x = 0.0, 0.1, 0.2 and 0.3) composition does not transform from normal ferroelectric to relaxor ferroelectric. The diffusivity enhances with increment in Sr concentration in the present composition range. It is observed that with enhancement in Sr content, the transition temperature decreases for all the studied compositions. The decrease in transition temperature may occur due to introducing a smaller ionic radius of Sr2+ at the site of a larger ionic radius of Ba2+. The morphological properties of all the samples are analyzed using scanning electron microscopy images. [ABSTRACT FROM AUTHOR]

Cadmium substituted Z-type hexaferrites are prepared via the sol-gel route. The phase temperature of pre-sintered materials is studied from the thermal analysis. The single-phase of Z-type hexaferrite is found through X-ray diffraction investigation. The Crystallite sizes of the entire samples are evaluated within the range of 14–15 nm. The Fe–O stretching vibration band at 566 cm−1 is confirmed from Fourier transform infrared spectroscopy. Saturation magnetization (M s) coercivity (H c) and remanence (M r) is examined by a vibrating sample magnetometer. The magnitude of M s has been increased from 45.41 to 56.35 emu/g with an increase of Cd2+ concentration. The magnitude of H c increased from 950.79 to 2186.95 Oe with an increment of Cd2+ concentration. Small values of squareness ratio (less than 0.5) showed the hard and single magnetic domain nature of the materials. The dielectric properties were analyzed using an impedance analyzer. Dielectric parameters show an increasing trend with the substitution of Cd2+. The maximum values of quality factor up to 17,000 and 10,000 are observed for sample Ba 2 · 85 Cd 0 · 15 Co 2 Fe 24 O 41 at 1 GHz and 2.7 GHz, respectively. The high value of the Q-factor shows that these ferrites can be applicable for the formation of resonant circuits and multilayer chip inductors. [ABSTRACT FROM AUTHOR]