Search NASA⌕ Search

SEARCH · Search NASA

Results for “diamond crystals”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Experimental setup for high-resolution characterization of crystal optics for coherent X-ray beam applications

Stanford Synchrotron Radiation Lightsource serves a wide scientific community with its variety of X-ray capabilities. Recently, a wiggler X-ray source located at beamline 10-2 has been employed to perform high-resolution rocking curve imaging (RCI) of diamond and silicon crystals. X-ray RCI is invaluable for the development of upcoming cavity-based X-ray sources at SLAC, including the cavity-based X-ray free-electron laser and X-ray laser oscillator. In this paper, the RCI apparatus is described and experimental results are provided to validate its design. Future improvements of the setup are also discussed.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Hybrid Integration of GaP Photonic Crystal Cavities with Silicon-Vacancy Centers in Diamond by Stamp-Transfer

Optically addressable solid-state defects are emerging as some of the most promising qubit platforms for quantum networks. Maximizing photon-defect interaction by nanophotonic cavity coupling is key to network efficiency. We demonstrate fabrication of gallium phosphide 1-D photonic crystal waveguide cavities on a silicon oxide carrier and subsequent integration with implanted silicon-vacancy (SiV) centers in diamond using a stamp-transfer technique. The stamping process avoids diamond etching and allows fine-tuning of the cavities prior to integration. After transfer to diamond, we measure cavity quality factors (Q) of up to 8900 and perform resonant excitation of single SiV centers coupled to these cavities. For a cavity with a Q of 4100, we observe a 3-fold lifetime reduction on-resonance, corresponding to a maximum potential cooperativity of C = 2. In conclusion, these results indicate promise for high photon-defect interaction in a platform which avoids fabrication of the quantum defect host crystal.

Purcell enhancement↗
NASA NTRS1982

Exit chipping in ID sawing of silicon crystals

The processes involved in exit chipping which may occur in the internal diameter diamond sawing of silicon crystals were examined. An interpretation of chipping observations is given in terms of crack propagation as acted upon by the sawing stresses. Since the exit chips are roughly parallel to saw marks, the general locus of the crack must be determined by contact stresses although the exact locus depends on already existing subfractures located in the kerf region which are caused by more than one abrasive particle. The crack starts at either edge since these are weak areas in flexure. In the more extensive "saw fracture", the fracture plane often changes part-way across the slice to be other than parallel to the saw mark because the speed of the crack accelerates beyond the speed of the blade travel; i.e., outstrips the advance of the contact stress field. The influences of various external factors on the opening of the crack are divided into two types: factors that wedge the crack apart and those that bend the slice away from the crystal. From a consideration of these factors, conditions for minimizing exit chipping are defined.

Dyer, L. D.↗
DOE OSTI2023

Soft, malleable double diamond twin

A twin boundary (TB) is a common low energy planar defect in crystals including those with the atomic diamond structure (C, Si, Ge, etc.). We study twins in a self-assembled soft matter block copolymer (BCP) supramolecular crystal having the double diamond (DD) structure, consisting of two translationally shifted, interpenetrating diamond networks of the minority polydimethyl siloxane block embedded in a polystyrene block matrix. The coherent, low energy, mirror-symmetric double tubular network twin has one minority block network with its nodes offset from the (222) TB plane, while nodes of the second network lie in the plane of the boundary. The offset network, although at a scale about a factor of 10 3 larger, has precisely the same geometry and symmetry as a (111) twin in atomic single diamond where the tetrahedral units spanning the TB retain nearly the same strut (bond) lengths and strut (bond) angles as in the normal unit cell. In DD, the second network undergoes a dramatic restructuring—the tetrahedral nodes transform into two new types of mirror-symmetric nodes (pentahedral and trihedral) which alternate and link to form a hexagonal mesh in the plane of the TB. The collective reorganization of the supramolecular packing highlights the hierarchical structure of ordered BCP phases and emphasizes the remarkable malleability of soft matter.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Spin-optomechanical cavity interfaces by deep subwavelength phonon-photon confinement

A central goal of quantum information science is transferring qubits between space, time, and modality. Spin-based systems in solids are promising quantum memories, but high-fidelity transfer of their quantum states to telecom optical fields remains challenging. Here, we introduce a phonon-mediated interface between spins in a diamond nanobeam optomechanical crystal and telecom optical fields by a simultaneous deep-subwavelength confinement of optical and acoustic fields with mode volumes $V_{\textrm{mech}}$$/Λ^3_\textrm{p} ~ 10^{-5}$ and $V_{\textrm{opt}}$$/λ^3 ~ 10^{−3}$, respectively. This confinement boosts the spin-mechanical coupling rate of Group-IV silicon vacancy (SiV − ) centers by an order of magnitude to ~ 32 MHz while retaining high acousto-optical couplings. The optical cavity couples to the spin irrespective of the emitter’s native excited states, avoiding spectral diffusion. Using Quantum Monte Carlo simulations, we estimate heralded entanglement fidelities exceeding 0.96 between two such interfaces. We anticipate broad utility beyond diamond emitter-telecom systems to most solid-state quantum memories.

Raniwala, Hamza [Massachusetts Inst. of Technology↗
DOE OSTI2020

Phase equilibrium of liquid water and hexagonal ice from enhanced sampling molecular dynamics simulations

We study the phase equilibrium between liquid water and ice Ih modeled by the TIP4P/Ice interatomic potential using enhanced sampling molecular dynamics simulations. Our approach is based on the calculation of ice Ih-liquid free energy differences from simulations that visit reversibly both phases. The reversible interconversion is achieved by introducing a static bias potential as a function of an order parameter. The order parameter was tailored to crystallize the hexagonal diamond structure of oxygen in ice Ih. Furthermore, we analyze the effect of the system size on the ice Ih-liquid free energy differences, and we obtain a melting temperature of 270 K in the thermodynamic limit. This result is in agreement with estimates from thermodynamic integration (272 K) and coexistence simulations (270 K). Since the order parameter does not include information about the coordinates of the protons, the spontaneously formed solid configurations contain proton disorder as expected for ice Ih.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Materials Data on Sn by Materials Project

Sn is diamond structured and crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Sn is bonded to four equivalent Sn atoms to form corner-sharing SnSn4 tetrahedra. All Sn–Sn bond lengths are 2.88 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Se by Materials Project

Se is diamond structured and crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Se is bonded to four equivalent Se atoms to form corner-sharing SeSe4 tetrahedra. All Se–Se bond lengths are 2.75 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Si by Materials Project

Si is diamond structured and crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Si is bonded to four equivalent Si atoms to form corner-sharing SiSi4 tetrahedra. All Si–Si bond lengths are 2.37 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sb2O3 by Materials Project

Sb2O3 is diamond structured and crystallizes in the cubic Fd-3m space group. The structure is zero-dimensional and consists of eight tetraantimony hexaoxide molecules. Sb3+ is bonded in a distorted T-shaped geometry to three equivalent O2- atoms. All Sb–O bond lengths are 2.01 Å. O2- is bonded in a bent 120 degrees geometry to two equivalent Sb3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on As2O3 by Materials Project

As2O3 is diamond structured and crystallizes in the cubic Fd-3m space group. The structure is zero-dimensional and consists of eight chebi:30621 molecules. As3+ is bonded in a distorted trigonal non-coplanar geometry to three equivalent O2- atoms. All As–O bond lengths are 1.83 Å. O2- is bonded in a bent 120 degrees geometry to two equivalent As3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ge by Materials Project

Ge is diamond structured and crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Ge is bonded to four equivalent Ge atoms to form corner-sharing GeGe4 tetrahedra. All Ge–Ge bond lengths are 2.50 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SbN9 by Materials Project

SbN9 is diamond structured and crystallizes in the trigonal R-3 space group. The structure is zero-dimensional and consists of six SbN9 clusters. Sb3+ is bonded in a 3-coordinate geometry to three equivalent N+0.33- atoms. All Sb–N bond lengths are 2.17 Å. There are three inequivalent N+0.33- sites. In the first N+0.33- site, N+0.33- is bonded in a single-bond geometry to one N+0.33- atom. The N–N bond length is 1.15 Å. In the second N+0.33- site, N+0.33- is bonded in a linear geometry to two N+0.33- atoms. The N–N bond length is 1.23 Å. In the third N+0.33- site, N+0.33- is bonded in a distorted bent 120 degrees geometry to one Sb3+ and one N+0.33- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ge2C2(SF2)3 by Materials Project

Ge2C2(SF2)3 is diamond structured and crystallizes in the cubic Fd-3m space group. The structure is zero-dimensional and consists of eight 1,3,5,7-tetrakis(trifluoromethyl)-2,4,6,8,9,10-hexathia-1,3,5,7-tetragermatricyclo[3.3.1.1^{3,7}]decane molecules. Ge4+ is bonded in a trigonal non-coplanar geometry to three equivalent S2- atoms. All Ge–S bond lengths are 2.24 Å. C2+ is bonded in a trigonal non-coplanar geometry to three equivalent F1- atoms. All C–F bond lengths are 1.36 Å. S2- is bonded in a distorted water-like geometry to two equivalent Ge4+ and two equivalent F1- atoms. Both S–F bond lengths are 3.23 Å. F1- is bonded in a single-bond geometry to one C2+ and one S2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ge2C2(SeF2)3 by Materials Project

Ge2C2(SeF2)3 is diamond structured and crystallizes in the cubic Fd-3m space group. The structure is zero-dimensional and consists of eight selenium;trifluoromethylgermanium molecules. Ge4+ is bonded in a trigonal non-coplanar geometry to three equivalent Se2- atoms. All Ge–Se bond lengths are 2.38 Å. C2+ is bonded in a trigonal non-coplanar geometry to three equivalent F1- atoms. All C–F bond lengths are 1.36 Å. Se2- is bonded in a 2-coordinate geometry to two equivalent Ge4+ and two equivalent F1- atoms. Both Se–F bond lengths are 3.28 Å. F1- is bonded in a single-bond geometry to one C2+ and one Se2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C by Materials Project

C is diamond structured and crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. C is bonded to four equivalent C atoms to form corner-sharing CC4 tetrahedra. All C–C bond lengths are 1.55 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LiCa4 by Materials Project

LiCa4 is diamond structured and crystallizes in the cubic Fd-3m space group. The structure is zero-dimensional and consists of eight LiCa4 clusters. Li is bonded in a tetrahedral geometry to four equivalent Ca atoms. All Li–Ca bond lengths are 2.86 Å. Ca is bonded in a distorted single-bond geometry to one Li atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on AuCl4 by Materials Project

AuCl4 is diamond structured and crystallizes in the tetragonal I4_1/amd space group. The structure is zero-dimensional and consists of four AuCl4 clusters. Au is bonded in a rectangular see-saw-like geometry to four equivalent Cl atoms. All Au–Cl bond lengths are 2.30 Å. Cl is bonded in a single-bond geometry to one Au atom.

36 MATERIALS SCIENCE↗