A5056479050- Advanced ceramic materials synthesis
- Advanced materials and composites
- MXene and MAX Phase Materials
- Thermal properties of materials
- Microwave Dielectric Ceramics Synthesis
- Luminescence Properties of Advanced Materials
- Boron and Carbon Nanomaterials Research
- Perovskite Materials and Applications
- Graphene research and applications
- Bone Tissue Engineering Materials
- Aluminum Alloys Composites Properties
- Semiconductor materials and devices
- Energetic Materials and Combustion
- Metal and Thin Film Mechanics
- High-pressure geophysics and materials
- Advanced Battery Materials and Technologies
- Graphene and Nanomaterials Applications
- Ammonia Synthesis and Nitrogen Reduction
- Solid State Laser Technologies
- Ferroelectric and Piezoelectric Materials
- Synthesis and Biological Evaluation
- Fiber-reinforced polymer composites
- Phase Change Materials Research
- Polymer Surface Interaction Studies
- Toxin Mechanisms and Immunotoxins
State Key Laboratory of New Ceramics and Fine Processing
2020-2024
Tsinghua University
2013-2024
Luliang University
2024
Zhoukou Normal University
2024
Shanghai Jiao Tong University
2002
Covalently bonded ceramics exhibit preeminent properties-including hardness, strength, chemical inertness, and resistance against heat corrosion-yet their wider application is challenging because of room-temperature brittleness. In contrast to the atoms in metals that can slide along slip planes accommodate strains, covalently require bond breaking strong directional characteristics covalent bonds. This eventually leads catastrophic failure on loading. We present an approach for designing...
Multifunctional phosphors have significant application and scientific value are becoming a research hotspot in the field of luminescent materials. Herein, we report Mn4+-activated double-perovskite-type Sr2LuNbO6 multifunctional with excellent comprehensive properties fields optical temperature/pressure sensing w-LED lighting. The crystalline structure, elemental composition, optimal doping concentration, crystal-field strength, bandgap investigated detail, mechanisms concentration thermal...
Abstract Highly dense α ‐silicon nitride (Si 3 N 4 ) ceramics were densified at a lower temperature of 1450°C under moderate mechanical pressure 50 MPa from commercial ‐Si powder and with conventional Al 2 O –Y sintering additives. The fabricated exhibited hardness 19 GPa, which is higher than that the β usually obtained. effect in liquid phase studied. role dissolution–reprecipitation process particle rearrangement during densification α‐Si discussed.
Abstract Mn 4+ ‐activated double‐perovskite type Ca 2 ScSbO 6 (CSS) phosphors were synthesized via a high‐temperature solid‐state reaction. The phase purity and crystal structure of obtained samples investigated by powder X‐ray diffraction (XRD). successful incorporation ions into CSS lattice was confirmed the combination energy‐dispersive spectra (EDX) photoelectron (XPS) results. luminescent properties phosphors, including photoluminescence (PL) PL excitation (PLE) spectra, commission...
Abstract Si 3 N 4 ceramics with tailored gradient in color and microstructure were prepared by a rapid cost‐effective one‐step approach. The was obtained the manipulation of dissolution‐reprecipitation process, controlling sintering temperature additive content. In ceramics, β‐phase content gradually changed from 84% to 11%. exhibited white on one side showed hardness 19 GPa fracture toughness 7 MPa·m 1/2 may be suitable for bio‐implantation applications.
Abstract A novel deep‐red‐emitting phosphor Ca 2 ScNbO 6 :Mn 4+ is prepared via a high‐temperature solid‐state reaction and its luminescent properties are systematically investigated. The results show that Mn ‐activated phosphors have broad absorption in ultraviolet region, bright deep‐red emission at 692 nm. optimal doping concentration, crystal‐field strength, internal quantum efficiency, mechanism of concentration thermal quenching effects discussed detail. Moreover, NaF flux screened out...
Stable multilayer films have been fabricated on the basis of alternating layer-by-layer assembly an azulene-based supra-amphiphile and a photoreactive polyanion. Moreover, one component supra-amphiphile, pyrene, can be removed from films, generating functional surface-imprinted films. Uptake experiments show that are capable recognizing hydrophobic template molecule in water. The reloading process increases with increasing temperature. loading capacity regulated by change layer pairs. In...
Abstract α‐SiAlON is well known for its excellent mechanical properties, but thermal properties are less investigated. In this work, we investigate the conductivity of Ca ceramics with varying m and n values prepared samples by spark plasma sintering (SPS) at 1600°C or gas pressure (GPS) 1800°C 1900°C. The showed conductivities ranging from 4.6 to 10.7 W/(mK) 25°C. It was found that could be reduced increasing either both. Besides, SPS had lower compared those GPS due their smaller grain...
Abstract Silicon nitride (Si 3 N 4 ) ceramics with initial β‐Si content from 3% to 88% were prepared by spark plasma sintering 1450 1700°C. The effect of on the phase transition, microstructure evolution, and mechanical properties Si was studied. existence accelerated α–β transition. When 12% 46%, aspect ratio grains increased. 88%, mainly composed short rod‐like grains. As increased, densification process slowed down. hardness fracture toughness samples reached about 18 GPa 6 MPa·m 1/2 . It...
Abstract Si3N4 ceramics with improved thermal conductivity and mechanical properties were prepared by carbothermal reduction two‐step sintering. The addition of 2 wt% C led to the development an intergranular phase YNSiO2 reduced oxygen content. Notably, setting pre‐sintering temperature at 1450°C promoted formation a rough bimodal morphology within ceramics. Furthermore, extended holding period 1850°C resulted in additional grain growth elimination phases. specimens produced for 3 h...
Abstract Coarse‐grained β‐Si 3 N 4 powders were prepared by combustion synthesis under 2 pressure of 6 MPa, with a low diluent content not more than 10 wt.% and high reaction temperature >1900°C. was obtained as the major phase in products, except for small amount residual Si. The addition carbon black effective to reduce Si, but resulted formation β‐SiC when too much used. coarse‐grained consisted crystals an average thickness µm, some thicker 20 µm. growth mechanism coarse discussed,...
Abstract β‐SiC powders with different particle morphologies were prepared by combustion synthesis in an N 2 atmosphere, carbon black, fiber, graphene, and graphite as sources. With black the source, single‐phase nanopowder average size around 20 nm was obtained. From fiber SiC fibers sheets produced, which polycrystalline consisted of lots nanocrystals random orientations. It proposed that occurs gas–solid reaction growth is confined to particles. In controlled SiC, morphology precursor...
Abstract Si 3 N 4 powders were prepared by combustion synthesis with 1‐ and 3‐μm α‐Si , β‐Si diluent BN inert diluent. The maximum temperatures of samples boron nitride (BN) as a are about 1500–1600°C lower than that diluents 1600–1800°C. Moreover, the newly formed contents in synthesized products over 90 wt% much higher those 20–40 wt%. strip‐like rod‐like grains, radiative shaped grains can be observed products. Finally, effect on α‐phase content is discussed, which provides key guidance...
Abstract β‐Si 3 N 4 powder with well‐dispersed spherical particles was synthesized by liquid‐phase modified carbothermal reduction and nitridation. The influence of the type content additives on particle morphology investigated. liquid phase formed at reaction temperature modifies Si powder. products precipitated along liquid‐solid interface, thus forming a promoting transformation from α‐Si to . has strong formation viscosity hence affects product morphology. In samples CaF 2 CaO additives,...