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Owing to the energy-efficient attributes of electrochromic technology, there has been a growing emphasis on the fabrication of electrochromic devices with high-contrast and stable performance. As an electron donor, the deliberate incorporation of oxygen vacancies into an electrochromic material is poised to significantly elevate the film's electrochromic characteristics. In this study, we successfully synthesized one-dimensional W 18 O 49 nanowires thin films with enhanced oxygen vacancies using a straightforward combination of solvothermal reactions and annealing in Ar. In comparison to films annealed in air, those treated in argon (Ar) exhibited a higher concentration of oxygen vacancies, resulting in improved light absorption characteristics. The optimal annealing conditions were determined to be 400 °C for 40 min. Under these conditions, the thin film demonstrates enhanced electrochromic performance, exhibiting a notable 71.6% modulation in transmittance, a 27.2% increase compared to the air condition. It displays a rapid response time (T b = 3.3 s, T c = 3 s), high coloration efficiency (CE = 55.9 cm2 C−1), and excellent cycling stability (with a ΔT retention rate of 93.9% after 750 cycles). [ABSTRACT FROM AUTHOR]

Within the framework of the model of the nonlocal thermoelastic peak of low-energy ion, the formation of intrinsic stress in a carbon coating deposited from the vacuum arc plasma in the argon atmosphere is theoretically studied. It is shown that the flow of particles bombarding the deposited coating contains, along with C+ ions, also Ar+ ions involved in the formation of intrinsic stress in the coating. The flux density of Ar+ ions resulting from ionization losses of C+ ions passing through the argon atmosphere is proportional to both the flux density of C+ ions and the density (pressure) of argon. Expressions are obtained for the intrinsic stress in the deposited carbon coating depending on the bias potential on the substrate and the argon pressure for the cases of both constant and pulsed potentials. The analysis of the obtained expressions shows that the intrinsic stress in the carbon coating decrease with increasing argon pressure.

(Zn1-x-yAlxBy)O (x = 0, y = 0, x = 0.02 and y = 0.005, 0.01, 0.02) ceramics have been synthesised via conventional solid-state reaction (SSR) method. Each ceramic formed as a single phase with a dense microstructure. The Seebeck coefficient, power factor, and electrical resistivities were determined for all these ceramics. Very interesting changes have been observed in the thermoelectric properties of ZnO ceramics sintered in the atmosphere of argon gas at 1450 °C via Al and B codoping. The power factor ~6.332 × 10 −4 W K − 2 m−1 and Seebeck's coefficient ~ −89.85 µ V K −1 along with lowest electrical resistivity ~ 1.224 m Ω cm at 700.0 °C was obtained for the composition with y = 0.01, i.e., (Zn0.097Al0.02B0.01)O. [ABSTRACT FROM AUTHOR]

In this study, the surface chemistry, skeleton structure and thermal safety of three different methylsilyl modified silica aerogels (SAs) have been explored under heat treatment in an argon atmosphere. With the heat treatment temperature increasing to 700 °C, the secondary particles aggregate, the silica skeletons get denser and the pore volumes diminish. Meanwhile, the excellent thermal insulation performance is still maintained, with the thermal conductivity not exceeding 30 mW⋅ m −1⋅ k −1. It finds the Si-(CH 3) 3 groups are converted to Si-(CH 3) 2 groups, and further transformed to Si-CH 3 groups. The generated and original Si-CH 3 groups can be maintained until 700 °C, which constitutes the chemical basis for the high-temperature hydrophobicity. The improved thermal stability and reduced gross calorific values both verify that the thermal safety of the heat-treated SAs has been obviously enhanced. This study provides an engineering reference for the high-temperature thermal insulation application for hydrophobic SAs. [ABSTRACT FROM AUTHOR]

The present work focuses on the influence of SiC content on the morphology and microstructure of in-situ synthesized ZrB 2 –SiC composite using ZrO 2 , B 4 C and Si via a single-step reduction process under argon atmosphere. The ZrB 2 –SiC composite was synthesized with variation in mole content of starting reactant and calcination temperature. The molar ratio of ZrO 2 :B 4 C:Si was increased from 2:1.5:0.5 to 2:1.67:1.34 at 1300–1500 °C, resulting SiC content increased and average grain size reduced. Major phase of ZrB 2 and SiC were detected in the composite using XRD and XPS techniques. Morphology and microstructure of synthesized ZrB 2 and SiC were determined by SEM and TEM analysis. The results revealed that a homogenous layer of uniformly dispersed SiC particles was exhibited over the surface of rod and spherical granulation of ZrB 2 , which restricted the grain growth of ZrB 2 particles during synthesis. With increasing the SiC content, the pinning effect on the grain boundary enhanced the dense structure of ZrB 2 –SiC composite. The feasibility of reaction for the synthesis of ZrB 2 –SiC composite was confirmed by thermodynamic calculation and experimental results. It can be concluded from experimental results that the composite was synthesized below the thermodynamically calculated synthesis temperature due to maintaining moderate vacuum backfilled by argon. • Present work is aimed to study the influence of SiC content on the morphology and microstructure of in-situ synthesized ZrB 2 –SiC composite using ZrO 2 , B 4 C and Si via a single-step reduction process under argon atmosphere. • The impurity-free dense ZrB2–SiC composite is synthesized using a different molar ratio of starting reactant at a lower calcination temperature. • The tiny SiC particle was homogeneously distributed on the ZrB2 particles, which restricted its grain growth and provided a dense ZrB2–SiC composite. • With increasing the SiC content up to an optimum limit, oxide-free ZrB 2 –SiC composite was obtained along with the pinning effect on the grain boundary enhancing the dense structure of the ZrB 2 –SiC composite. [ABSTRACT FROM AUTHOR]

Eu3+-doped zirconia has been considered an efficient phosphor material due to its multi-colour emissive photoluminescence properties. Tuning of emission colour is possible by changing the Eu3+-ions concentration and excitation wavelength. The influence of Eu3+-ions and excitation wavelength on the emission intensity, asymmetric ratio, CIE coordinates, and Judd-Ofelt parameters of the Eu3+-doped zirconia nanophosphors have been explored in this work. Ultra-fine nano-sized particles of pure tetragonal zirconia were observed when the samples were calcined under an argon atmosphere at 800 °C. The expansion and distortion of tetragonal zirconia has been confirmed from XRD and Raman Spectra of Eu3+-doped zirconia samples, respectively. The XPS analysis suggested elemental composition and incorporation of trivalent state of Eu-ions in Eu3+-doped zirconia sample calcined under argon calcination condition. Further, emission spectra of Eu3+-doped zirconia samples have been investigated at the excitation wavelength of 240 nm, 393 nm, and 463 nm. The emission spectra of 3 mol % and 6 mol % Eu3+-doped zirconia samples revealed several emission peaks in the range of 580–710 nm corresponding to the Eu3+-ions transition of 5D 0 → 7F j (=0 to 4). However, due to lower emission intensity, these transitions were not clearly visible up to 1 mol % Eu3+-ions. The CIE coordinates confirmed the tuning of emission colour in Eu3+-doped zirconia nanophosphor at different excitation wavelengths. The Judd-Ofelt parameters also suggested that the Eu3+-doped zirconia may be utilized for better optical gain. So, nano-sized Eu3+-doped zirconia phosphor materials may consider as a potential candidate for different luminescence applications. [Display omitted] • Eu3+-doped t-ZrO 2 nanoparticles have been prepared under Ar calcination atmosphere. • XRD and Raman suggest lattice expansion and distortion of t-ZrO 2 , respectively. • Emission of 3 and 6 mol% Eu3+-doped ZrO 2 varied with excitation wavelengths. • Asymmetric ratio and CIE coordinates suggest tuning of emission via different λ ex. [ABSTRACT FROM AUTHOR]