In this study, the antibacterial activity of cerium oxide nanoparticles on two Gram-negative and three Gram-positive foodborne pathogens was investigated. CeO₂ nanoparticles (CeO₂ nps) were synthesized by a Wet Chemical Synthesis route, using the precipitation method and the Simultaneous Addition of reactants (WCS–SimAdd). The as-obtained precursor powders were investigated by thermal analysis (TG–DTA), to study their decomposition process and to understand the CeO₂ nps formation. The composition, structure, and morphology of the thermally treated sample were investigated by FTIR, Raman spectroscopy, X-ray diffraction, TEM, and DLS. The cubic structure and average particle size ranging between 5 and 15 nm were evidenced. Optical absorption measurements (UV–Vis) reveal that the band gap of CeO₂ is 2.61 eV, which is smaller than the band gap of bulk ceria. The antioxidant effect of CeO₂ nps was determined, and the antibacterial test was carried out both in liquid and on solid growth media against five pathogenic microorganisms, namely Escherichia coli, Salmonella typhimurium, Listeria monocytogenes, Staphylococcus aureus, and Bacillus cereus. Cerium oxide nanoparticles showed growth inhibition toward all five pathogens tested with notable results. This paper highlights the perspectives for the synthesis of CeO₂ nps with controlled structural and morphological characteristics and enhanced antibacterial properties, using a versatile and low-cost chemical solution method.

A modified TFA-MOD method, using only barium trifluoroacetate, is presented. The yttrium and copper triflouroacetates were replaced by the alcoholic solutions of Cu and Y acetates dispersed in propionic acid. Fourier transformed infrared spectroscopy (FT-IR), thermal analyses (DTA/TG) coupled with mass spectrometry (MS) and X-ray diffraction analyses were used to study the decomposition of the precursor. The method permits the shortening of the pyrolysis time by a factor 4, with respect to conventional TFA-MOD method, due to the smaller amount of evolved hydrofluoric acid. Using this method 600 nm thick YBCO films were grown both on (100)SrTiO₃ and on CeO₂/YSZ/CeO₂/Pd buffered Ni-5at.%W substrates. The as obtained films exhibit good morphological, structural and superconducting properties with T_c (R=0) greater than 91K and with an out-of-plain texture of 0.24⁰ and 1.9⁰, respectively.

This work reports on the preparation of a BaZrO₃ (BZO) nanopowder by the chemical decomposition of an oxalate precursor starting from barium acetate and zirconium oxychloride. The X-ray peak profile analyses and the scanning electron microscopy (SEM) have indicated that the mean powder size ranges from 30nm to 340 nm for the thermal treatment temperature varying from 700°C to 1200°C, respectivelly. The as prepared powder has been used to manufacture YBCO-5 mol. % BZO composite targets from which epitaxial YBCO thin films on (100)SrTiO₃ substrate were ablated. The X-ray analysis have revealed that the BZO nanoislands are epitaxially grown throughout the YBCO film, having the same epitaxial relationship as YBCO. Moreover, as revealed by SEM, the presence of BZO considerably improves the morphology of the YBCO film. The critical temperature (T_c) registered a slight decrease with the BZO concentration. Nevertheless, the BZO addition resulted in an improvement of the critical current density, J_c. The J_cvsB curve exihibits a large plateau extended up to about 2.5 Tesla. The YBCO-BZO composite films showed pinning forces with a c-axis correlated character, as revealed by the angular behaviour of J_c.

We present a comparative study of vortex pinning in chemically deposited YBa ₂ Cu ₃ O _7-x /BaZrO ₃ nanocomposite films, with the aim of correlating the preparation method to the superconducting properties. Two sets of samples have been prepared by different low fluorine routes (one set followed the in situ approach), with different starting YBCO coating solution and with a different amount of BaZrO ₃ . The short-range vortex pinning properties have been assessed using a contactless microwave (48 GHz) technique, which yielded the vortex pinning constant (Labusch parameter) k _p and the vortex viscosity θ as a function of the applied field up to 0.8 T, and for temperatures between 60 K and T _c . The results were compared to more usual (long-range vortex motion) J _c measurements. Despite the supposed similarity in pinning as determined from J _c , we found significant differences between the pinning properties of the two sets of samples. It appears that the in situ approach results in stronger pinning at microwaves in the whole temperature range explored, and that this behavior is due to the smaller dimensions of BaZrO ₃ nanoparticles. This information can be very useful in the search of optimized chemical route to strong pinning superconducting nanocomposite materials.

Polymer assisted deposition (PAD) was used as an environmentally friendly, non-fluorine, growth method for superconducting YBa₂Cu₃O_7−x (YBCO) films. The kinetics of the thermal decomposition of the precursor powder was studied by thermogravimetry coupled with mass spectrometry (TG-QMS). YBCO films were spin coated on (100) SrTiO₃ (STO) single crystalline substrates, followed by a single step thermal treatment under wet and dry O₂ and O₂/N₂ mixture. The as-obtained films were epitaxially grown having a [001]YBCO||[001]STO out-of-plane epitaxial relationship and exhibited good superconducting properties with T_c (R = 0) > 88 K, transition widths, ΔT ≈ 2 K and critical current densities as high as 2.3 MA/cm² at 77 K and self magnetic field.

We report the preparation and characterization of epitaxial LaNiO₃ (LNO) thin films by chemical solution deposition method using lanthanum and nickel acetylacetonates as starting reagents dissolved in propionic acid. In order to obtain further information regarding the decomposition behavior of the film, the precursor solution was dried to obtain the precursor powder, which was investigated by thermal analyses and X-ray diffraction measurements (XRD). The LNO perovskite thin films were deposited by spin coating on SrTiO₃(100) single crystal substrates. A detailed study with different crystallization temperatures (600–900 °C) at two different heating ramps (5 and 10 °C/min) was performed. Oriented LaNiO₃ thin films with good out-of-plane textures were obtained with optimal surface morphologies.