The FIR reflectivity spectra of boron carbide, measured down to ω~10 cm(-1) between 100 and 800 K, are essentially determined by heavily damped plasma vibrations. The spectra are fitted applying the classical Drude-Lorentz theory of free carriers. The fitting Parameter Π=ωp/ωτ yields the carrier densities, which are immediately correlated with the concentration of structural defects in the homogeneity range. This correlation is proved for band-type and hopping conductivity. The effective mass of free holes in the valence band is estimated at m*/me~2.5. The mean free path of the free holes has the order of the cell parameters.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1088/0953-8984/26/42/425801 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Improving the Fracture Toughness of Boron Carbide via Minor Additions of SiC and TiB Through Hot-Press Sintering.
Materials (Basel)
December 2024
Analysis & Standards Center, Korea Institute of Ceramic Engineering & Technology (KICET), 101 Soho-ro, Jinju-si 52851, Republic of Korea.
Boron carbide (BC) is an essential material in various high-performance applications due to its light weight and hardness. In this work, BC-based composites were fabricated via a powder route consisting of powder mixing, precursor preparation, and hot-pressing under vacuum. The composites' mechanical properties and microstructure were analyzed to investigate the effect of adding minor second-phase particles.
View Article and Find Full Text PDFMechanochemical destruction of perfluorooctane sulfonate (PFOS) using boron carbide (BC).
J Hazard Mater
December 2024
State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESP), Beijing, China; Key Laboratory for Emerging Organic Contaminants Control (BKLEOC), Beijing, China; Laboratory for Environmental Frontier Technologies (BLEFT), School of Environment, Tsinghua University, Beijing 100084, China. Electronic address:
Widespread detection in soils and sediments underscores the potential threats posed by persistent, bioaccumulative and toxic perfluorooctane sulfonate (PFOS) to ecosystems and organisms. Nevertheless, the formidable energy of the C-F bond imparts stability and hampers degradation. This study investigates the potential of boron carbide (BC), a hard-ceramic material often utilized in armor and abrasion contexts, for degrading solid-phase PFOS through ball milling.
View Article and Find Full Text PDFA study on the mechanical and radiation shielding characteristics of concrete samples reinforced with brass alloy and boron carbide.
Appl Radiat Isot
December 2024
Bingöl University, Faculty of Arts and Science, Department of Physics, 12000, Bingöl, Türkiye.
In this study, the gamma radiation shielding properties of concrete samples reinforced with 10%, 20%, 30%, 40% and 50% of the cement weight of brass alloy were investigated. To test gamma shielding performance of the samples, mass and linear attenuation coefficients, half and tenth value layers, effective atomic number and radiation protection efficiency parameters were determined experimentally, theoretically and Monte Carlo simulations (GEANT4 and FLUKA). The studies were performed at 11 different gamma energies that range from 59.
View Article and Find Full Text PDFReduced Graphene Oxide Reinforces Boron Carbide with High-Pressure and High-Temperature Sintering.
Materials (Basel)
November 2024
Synergetic Extreme Condition High-Pressure Science Center, State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Qianjin Street, Changchun 130012, China.
Introducing a second phase has been an effective way to solve the brittleness of boron carbide (BC) for its application. Though reduced graphene oxide (rGO) is an ideal candidate for reinforcing the BC duo's two-dimensional structure and excellent mechanical properties, the toughness is less than 6 MPa·m, or the hardness is lower than 30 GPa in BC-graphene composites. A barrier to enhancing toughness is the weak interface strength between rGO and BC, which limits the bridging and pull-out toughening effects of rGO.
View Article and Find Full Text PDFCompetitive co-diffusion as a route to enhanced step coverage in chemical vapor deposition.
Nat Commun
December 2024
Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden.
Semiconductor devices are constructed from stacks of materials with different electrical properties, making deposition of thin layers central in producing semiconductor chips. The shrinking of electronics has resulted in complex device architectures which require deposition into holes and recessed features. A key parameter for such deposition is the step coverage (SC), which is the ratio of the thickness of material at the bottom and at the top.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!