The paper describes the sol–gel process applied to synthesize a mercury-free Ba₂Ca₂Cu₃O_x precursor and the physicochemical properties of an Hg_0.8Pb_0.2Ba₂Ca₂Cu₃O_8+δ high-temperature superconductor (HTS) polycrystalline sample. The Ba₂Ca₂Cu₃O_x precursor with desired chemical and phase compositions was obtained using...

La_1-xSr_xMnO₃ nanoparticles were synthesized by precipitation from diethylene glycol solution. Features of synthesis were studied using ¹Н, ¹³С, ¹³⁹La nuclear magnetic resonance (NMR) investigations. The obtained results showed that the complexation reaction between diethylene glycol and metal cations takes place during the synthesis. These complexes decomposed at 200?℃ and an amorphous precursor ...

Ceramics of Bi_0.9Ba_0.1Fe_0.925Ti_xO₃ (x = 0.0625, 0.08125, 0.0875, and 0.11) were prepared according to two doping strategies: one is called single-step doping in which Ba and Ti were doped together in calcination, while the other one is called two-step doping in which Ba and Ti were doped in calcination and sintering, respectively. Compared with samples prepared with single-step doping, those prepared with two-step doping hav...

The addition of magnetic Co_0.5Zn_0.5Fe₂O₄ nanoparticles to the superconducting Cu_0.5Tl_0.5-1223 phase has been used to investigate the electrical resistivity behavior of the composite above the superconducting transition temperature T_c. This was studied according to the opening of spin gap and fluctuation conductivity. The results indicated that the pseudogap temperature (T^*) and superc...

Lead-free (1-x)Sr_0.1Bi_0.45Na_0.45TiO₃-xBi_0.5Li_0.5TiO₃ (x = 0-0.4) ceramics were successfully prepared by a solid-state reaction technique. The effects of amount of Bi_0.5Li_0.5TiO₃ on structure and electrical properties were examined. The X-ray diffraction (XRD) analysis revealed that all the investigated specimens have a perovskite structure. An obvious change in mi...

Hierarchical urchin-like γ-Al₂O₃ hollow microspheres were prepared by a hydrothermal method followed by a calcination process using Al(NO₃)₃·9H₂O as aluminum source, NH₃·H₂O as precipitating agent, and P123 as structure-directing agent (SDA). The obtained samples were investigated using X-ray diffraction (XRD), filed emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and N