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We have systematically studied the dielectric properties of epitaxial barium strontium titanate, Ba_1-xSr_xTiO₃(x = 0.0, 0.1, 0.2, …, 1.0), films on MgO substrates grown by pulsed laser deposition. The dielectric properties of Ba_1-xSr_xTiO₃ films at a frequency of 1 MHz and room temperature are a strong function of Ba/Sr ratio. The degree of electric field dependent dielectric constant is more pronounced with decrease of x values. The largest dielectric tunability and the figure of merit (or tunability/loss) are obtained at x = 0.3 and at x = 0.4, respectively.

Eu-doped SiAlON thin films were successfully prepared by co-sputtering method using $\alpha$-SiAlON and Eu₂O₃ ceramic target. The photoluminescence behaviors of the films are investigated as a function of Eu ions concentration and temperature. The doping concentration of Eu ions in films can be effectively controlled by adjusting the sputtering power of Eu₂O₃ target. XRD analysis and SEM morphology images illustrate that the Eu-doped SiAlON thin films are amorphous, dense, and smooth, no matter they experienced high temperature heat-treatment or not after co-sputtering deposition. An intense and broad blue emission band peaking at 416–450nm was exhibited when the films upon excitation at 275nm, proving a typical Eu${}^{2+}$ emission. The divalent state of Eu ions in films was further identified. As the sputtering power of Eu₂O₃ target increases, the emission peak of Eu${}^{2+}$ shows a red-shift. The prepared thin films possess a better resistant property of thermal quenching and the relative fluorescence intensity at 100^∘C can remain about 86% of its initial value at room temperature.

Superconducting Nb₃Sn films were synthesized via the ex-situ annealing of Nb-coated bronze precursors. The precursors were prepared by sputtering 2 $\mu$m of niobium film onto a bronze surface. The annealing was conducted in a vacuum tubular furnace at a temperature not higher than 700${}^{\circ }$C. By changing the annealing time and temperature, a series of Nb₃Sn samples with critical temperatures ($T_c)$ > 16 K were obtained. X-ray diffraction confirmed the existence of the cubic Nb₃Sn phase (A15 structure), whereas magnetic moment measurements indicated that critical temperature of the studied samples ranged from 16.2 to 16.5 K. Therefore, this study explores a new technique appropriate for creating copper-based Nb₃Sn thin-film-coated superconducting radio-frequency (TFSRF) cavities.

A Cu film with the ability to rapidly inactivate the COVID-19 virus was easily fabricated at approximately 23${}^{\circ }$C on a Na-free glass substrate. The well-adhered Cu films with thickness of approximately 16 $\mu$m and surface area of 8.71 10${}^{-3}$ m² g${}^{-1}$ were obtained by immersion of the glass substrate into an aqueous solution with dissolved Cu (II) complex of ammonia and ascorbic acid. The interface bonded between the film and glass substrate was very strong, such that the film did not peel off even when it was exposed to an ultrasonic wave of 100 mW (42 kHz) in water. The anti-COVID-19 activity in Dulbecco’s modified Eagle’s medium (DMEM) is effective within 2 h and is faster than that of commercial copper plates. The changes in the relative abundance of Cu₂O and CuO crystallines on the Cu film due to DMEM treatment and those in surface morphology were examined by X-ray diffraction peak analysis and field emission-scanning electron microscopy, respectively. The flame atomic absorption analyses of the recovered solutions after DMEM treatment indicated that the Cu ions from the Cu film with DMEM treatment for 1 hour at a concentration of 0.64 ± 0.03 ppm were eluted 2.3 times faster than those from the Cu plate. The rapid elution of Cu ions from Cu₂O crystallines on the film in the early stage is the primary factor in the inactivation of the COVID-19 virus, as elucidated from the time dependence of eluted Cu ions by DMEM treatment. Results from thermogravimetric and differential thermal analysis (TG-DTA) of the powder scratched from the Cu film suggested that a trace amount of organic residues remaining in the Cu film was important in the rapid activity.

In this study, submicron Sn${}^{4+}$-doped In₂O₃ hollow particles (indium-tin oxide (ITO)) with a lyrium shell-like surface were synthesized via solvothermal method. The appropriate addition of these particles into polyvinylidene fluoride (PVDF) films exhibits high visible light transmission and effective UV/IR blocking properties, surpassing those of ITO nanoparticles. This can be attributed to the reduced absorption of UV/IR radiation by the hollow ITO particles, as well as their higher diffuse reflectivity and thermal insulation.