A novel method is introduced in this study for producing ceramisite coarse aggregates that are both lightweight and possess high strength. The process involves utilizing fly ash as the primary material, along with coal ash floating beads (CAFBs) that have high softening temperature and a spherical hollow structure serving as the template for forming pores. This study examined the impact of varying particle size and quantity of floating beads on the composition and characteristics of ceramisite aggregates. Results showed that the high softening temperature of floating beads provided stability to the spherical cavity structure throughout the sintering process. Furthermore, the pore structure could be effectively tailored by manipulating the size and quantity of the floating beads in the manufacturing procedure. The obtained ceramisite aggregates feature a compact outer shell and a cellular inner core with uniformly distributed pores that are isolated from each other and mostly spherical in form. They achieve a low density ranging from 723 to 855 kg/m³, a high cylinder compressive strength between 8.7 and 13.5 MPa, and minimal water absorption rates of 3.00 to 4.09%. The performance metrics of these coarse aggregates significantly exceeded the parameters specified in GB/T 17431.1-2010 standards.

Lead-free Mn²⁺-based metal halide materials are now being considered as clean candidates for backlight displays and lights due to the d–d transition, diverse components, and environmental friendliness. Therefore, efficient and stable Mn²⁺-based metal halide phosphors are in great demand for practical applications. In this work, adopting the mixed-ligand strategy, a series of [(CH₃)₄N]_2−x[(C₂H₅)₄N]_xMnCl₄ phosphors were synthesized by mechanochemical process. With the increase molar ratio of (CH₃)₄N/(C₂H₅)₄N, the phase of phosphors is transformed from orthorhombic to tetragonal. Compared to [(CH₃)₄N]₂MnCl₄ and [(C₂H₅)₄N]₂MnCl₄ phosphors, the mixed-ligand strategy significantly boosts the green emission intensity of Mn²⁺-based metal halide phosphors. The obtained [(CH₃)₄N][(C₂H₅)₄N]MnCl₄ phosphors exhibit a high photoluminescence quantum yield (PLQY) of 83.78% under 450 nm excitation, which is attributed to the modulation of the adjacent [MnCl₄]₂- distance by using the different chain length of organic cations, effectively suppressing non-radiative recombination. Additionally, the [(CH₃)₄N][(C₂H₅)₄N]MnCl₄ phosphors exhibit a green emission at 516 nm, narrow full width at half-maximum (FWHM) of 45.53 nm, and good thermal stability. The constructed white light-emitting diode (WLED) device exhibits a wide color gamut of 108.3% National Television System Committee, demonstrating the suitability of the [(CH₃)₄N][(C₂H₅)₄N]MnCl₄ phosphors as a green emitter for WLED displays and lightings. This work provides a new way to modulate the PL performance of manganese-based metal halides for application in the optoelectronic field.

Hybrid manganese bromides have emerged as promising lead-free narrow-band green emitters for wide-gamut displays, but their practical application is still limited by insufficient operational stability. Herein, Zn²⁺ substitution is employed to enhance the stability of tetraethylammonium manganese bromide (TEA₂MnBr₄) microcrystals (MCs) synthesized via an ultrafast self-assembly method. With increasing Zn²⁺ contents, the photoluminescence intensity of TEA₂Mn_1−xZn_xBr₄ MCs gradually decreases, while the x = 0.10 MCs still exhibit efficient narrow-band green emission at 518 nm and a high photoluminescence efficiency of about 85% under blue excitation. More importantly, Zn²⁺ incorporation substantially enhances the storage and thermal stability, as well as operational stability of the corresponding green LED devices (retaining above 99% of initial luminous efficacy after 160 h continuous operation at 20 mA). Finally, a white LED fabricated using the x = 0.10 MCs achieves a high luminous efficiency of about 136 lm/W and covers about 112% of the National Television System Committee 1931 color gamut. These results demonstrate that Zn²⁺ substitution is an effective strategy for stabilizing hybrid manganese bromide emitters and highlight their potential for lead-free wide-gamut display applications.

Flexible PbZr_0.52Ti_0.48O₃ (PZT) films have a wide application prospect in wearable devices. In this work, PZT films were fabricated on LaNiO₃–based Si substrates and mica substrates, respectively. The effects of Si substrates and mica substrates on the dielectric and ferroelectric properties of PZT films were studied. The stability of PZT films on different substrates was discussed by controlling temperature and frequency. The optimal annealing temperature for preparing PZT films on LaNiO₃–based Si substrates and mica substrates is 750 °C. The dielectric and ferroelectric properties of PZT films vary with the substrates. The diffraction peak of PZT films deposited on mica substrates shifted to the left compared with that deposited on Si substrates, due to difference of the expansion coefficients. The as–prepared PZT films exhibit a good ferroelectric property at a frequency in the range of 100 Hz~1000 Hz. Moreover, PZT films deposited on mica substrates have larger remanent polarization values and coercive fields than PZT films deposited on Si substrates. With the elevation in temperature, the dielectric constant of PZT films gradually enhance. And as–prepared PZT films at an annealing temperature of 750 °C have a better dielectric temperature stability. PZT films grown on Si substrates exhibit more excellent dielectric temperature stability than that of PZT films grown on mica substrates.

Silicon carbide (SiC) whiskers are effective reinforcements for carbon-containing refractories; however, their application is restricted by the inherently low reactivity of graphite, which is commonly used as an internal carbon source. In this study, low-cost coke and silicon powder were used as the carbon and silicon sources to synthesize SiC whiskers via a graphite-burial heat treatment process. The structural evolution of coke and the reaction behavior of the coke–Si system at different temperatures were systematically characterized. The results reveal that coke exhibits a TG-DSC mass loss of 16.01% and undergoes progressive structural rearrangement and enhanced short-range ordering at 1200–1400 °C while retaining a predominantly turbostratic carbon structure and morphological stability. At 1100–1200 °C, SiC whiskers form predominantly within pores, and this distribution is consistent with a gas-phase-assisted VS-type growth pathway; the normalized crystalline SiC fractions remain relatively low (~4–11%). A pronounced enhancement of SiC formation occurs at 1300 °C, where the crystalline Si phase becomes undetectable by XRD and abundant SiC whiskers spread from localized pore regions to the matrix surface. The enhanced whisker formation at 1300–1400 °C is attributed to accelerated reaction and mass-transfer processes at elevated temperatures. The synthesized whiskers consist of crystalline β-SiC, and those formed at 1400 °C exhibit high-density stacking faults and pronounced radial coarsening, with representative diameters of approximately 35–80 nm in the TEM images. The structural evolution of coke from a defect-rich state toward a more ordered turbostratic structure occurs concurrently with the temperature-dependent evolution of SiC nucleation and growth and may contribute to the availability of reaction sites and transport pathways, establishing coke as a promising carbon source for the in-situ synthesis of SiC whiskers in refractory applications.

Blue-excitable lead-free metal halide microcrystals (MCs) with high efficiency and narrow emission are highly desired for next-generation wide-gamut displays. Herein, an ultrafast self-assembly strategy is developed to prepare hybrid manganese bromide MCs with tunable alkyl-chain lengths. With increasing alkyl-chain length, the emission intensity of the obtained MCs first improves significantly and then deteriorates, accompanied by a gradual narrowing of the full width at half maximum (FWHM) from 46.37 to 41.97 nm. The optimized [(C₂H₅)₄N]₂MnBr₄ MCs exhibit strong narrow-band green emission at 518 nm with a FWHM of 43.30 nm and a high photoluminescence quantum yield of 98.70% under 455 nm excitation. This superior emission performance is ascribed to cooperative weak interactions, an appropriate Mn-Mn distance, and highly localized electronic transitions within isolated [MnBr₄]²⁻ tetrahedra. Moreover, the [(C₂H₅)₄N]₂MnBr₄ MCs show moderate thermal stability, retaining 52.03% of their initial emission intensity at 413 K. By integrating [(C₂H₅)₄N]₂MnBr₄ with K₂SiF₆: Mn⁴⁺ red phosphors on a blue chip, a white light-emitting diode with a high luminous efficacy of 134.60 lm/W and a wide gamut of 112.6% NTSC is achieved, demonstrating the great promise of ultrafast-assembled hybrid manganese bromides for efficient and wide gamut display backlighting.