Shock Compression of Boron Carbide: A Quantum Mechanical Analysis

Taylor, DeCarlos E.

doi:10.1111/jace.13711

Cited by 48 publications

(35 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The temperature behavior of this ribbon had previously been calibrated using the known phase transitions and thermal expansion of the corundum reference. [ 56 ] The sample was heated from 300 K to 1173 K at a rate of 10 K/min and the ramp was stopped for each diffractogram to avoid any temperature change during the data collection.…”

Section: Methodsmentioning

confidence: 99%

Tuneable Nanostructuring of Highly Transparent Zinc Gallogermanate Glasses and Glass‐Ceramics

Chenu

Véron

Genevois

et al. 2014

Advanced Optical Materials

View full text Add to dashboard Cite

routes [ 9,10 ] have been recently reported. Technical challenges remain to produce these transparent ceramic materials (complicated and time-consuming procedures to avoid porosity, [ 11 ] limited compositions, segregation of doping agents, etc.). Many of these obstacles can be avoided via the use of glass-ceramic technology. [ 12 ] Therefore, the development of transparent glassceramics is of great interest for many promising optical applications [ 13 ] (solar concentrators, [ 14 ] optical memory media, [ 15 ] telescope mirrors, [ 16 ] amplifi ers, [ 17 ] electrooptical devices [ 18 ] ). Unlike single crystals and polycrystalline sintered ceramics, glass-ceramic materials offer considerable advantages such as a wider range of accessible chemical compositions, fabrication of complex shapes, and largescale production by fast and cost-effi cient glass-forming processes. The absence of porosity, control of the microstructure, and high transparency allow a large variety of optical glass-ceramics to be designed and commercialized.Glass-ceramic technology is generally based on the controlled crystallization of glass. [ 12 ] According to the Rayleigh-GansDebye [ 19 ] and Hendy theories, [ 20 ] the retention of transparency during glass crystallization typically requires a homogeneous distribution of nanoscale crystals in the glass-ceramic material to minimize light scattering. Nucleating agents (such as ZrO 2 and TiO 2 ) are thus often added in the parent glass to produce, by heat treatment, uniformly dispersed nanocrystals. [ 21 ] Nevertheless, a few exceptions with large crystal sizes (β-quartz- [ 16 ] and Na 2 O-CaO-SiO 2 -based glass-ceramics [ 22 ] ) have been reported, and their transparency is directly linked to a very small refractive index difference between the amorphous and crystalline phases. Much attention has been devoted to transparent silicate glass-ceramics, which often present low thermal expansion, thermal stability, and high transparency in both visible and near-infrared ranges. [ 12,16 ] However, silicatebased glass-ceramics present a high phonon energy, which considerably limits their transparency in the infrared range and therefore their applications in this domain. The development of oxyfl uoride [23][24][25][26] and chalcogenide [ 27,28 ] glass-ceramics has extended the transparency toward the infrared range. These materials offer a real alternative allowing access to applications in telecommunications [ 25,26,29 ] (up-conversion devices, waveguide amplifi ers), although their poor chemical durability and complex fabrication (synthesis under a controlled New nanostructured gallogermanate-based glass materials exhibiting high transparency in the visible and infrared regions are fabricated by conventional melt-quenching. These materials can accommodate wide oxide compositions and present nanoscale phase separation, in the form of droplets well separated from the germanate matrix. The size of the nanostructures can be tailored depending on the composition. A single heat treatment then allows select...

show abstract

Section: Methodsmentioning

confidence: 99%

Tuneable Nanostructuring of Highly Transparent Zinc Gallogermanate Glasses and Glass‐Ceramics

Chenu

Véron

Genevois

et al. 2014

Advanced Optical Materials

View full text Add to dashboard Cite

show abstract

“…The Hugoniots were not determined past ∼100 GPa because of the emergence of imaginary frequencies in the phonon calculations by 120 GPa for CBC p . Recently, the solid Hugoniot of several boron carbide polytypes have been obtained via first-principles molecular dynamics simulations up to 80 GPa 50 . Of the polytypes considered in those calculations only the CBC p structure was also examined herein.…”

Section: A Solid Hugoniotmentioning

confidence: 99%

“…Nanoindentation experiments have found narrow amorphous bands and areas with local disorder as well as evidence for an amorphous phase above 40 GPa [40][41][42] . Numerous proposals have been put forward to explain the mechanism of amorphization and the gradual loss of strength that boron carbide experiences under pressure 22,[41][42][43][44][45][46][47][48][49][50][51][52] . These include: the bending of the CBC chains, the formation of new B-B bonds that are kinetically trapped, the presence of defects in the CBC chain, as well as the disassembly of the octahedra under shear stress.…”

Section: Introductionmentioning

confidence: 99%

Properties of B4C in the shocked state for pressures up to 1.5 TPa

et al. 2017

View full text Add to dashboard Cite

Density Functional Theory calculations using the quasi-harmonic approximation have been used to calculate the solid Hugoniot of two polytypes of boron carbide up to 100 GPa. Under the assumption that segregation into the elemental phases occurs around the pressure that the B11Cp(CBC) polytype becomes thermodynamically unstable with respect to boron and carbon, two discontinuities in the Hugoniot, one at 50 GPa and one at 90-100 GPa, are predicted. The former is a result of phase segregation, and the latter a phase transition within boron. First principles molecular dynamics (FPMD) simulations were employed to calculate the liquid Hugoniot of B4C up to 1.5 TPa, and the results are compared to recent experiments carried out at the Omega Laser Facility up to 700 GPa [Phys. Rev. B 94, 184107 (2016)]. A generally good agreement between theory and experiment was observed. Analysis of the FPMD simulations provides evidence for an amorphous, but covalently bound, fluid below 438 GPa, and an atomistic fluid at higher pressures and temperatures.

show abstract

“…Quantum molecular dynamics (QMD) simulation of boron carbide with different structures and stoichiometry was also performed by Taylor et al [20,21]. Again, it was shown, that uniaxial loading and shear stress are crucial for mechanical stability of boron carbide.…”

Section: Introductionmentioning

confidence: 97%