Single-crystal CVD diamonds as small-angle X-ray scattering windows for high-pressure research

Abstract

Small-angle X-ray scattering (SAXS) was performed on single-crystal chemical vapor deposition (CVD) diamonds with low nitrogen concentrations, which were fabricated by microwave plasma-assisted chemical vapor deposition at high growth rates. High optical quality undoped 500 mm-thick single-crystal CVD diamonds grown without intentional nitrogen addition proved to be excellent as windows on SAXS cells, yielding parasitic scattering no more intense than a 7.5 mm-thick Kapton film. A single-crystal CVD diamond window was successfully used in a high-pressure SAXS cell.

Developments in synthesis, characterization, and application of large, high-quality CVD single crystal diamond

“…The destabilized AL99 mutant of T4 lysozyme was characterized by up to 300 MPa [78]. No pressure dependence was observed for the window scattering, enabling unambiguous background subtraction and subsequent Guinier analysis [72]. The results demonstrate that high quality single-crystal CVD diamonds synthesized by MPCVD methods is an excellent window material for protein solution SAXS studies, while displaying superior mechanical properties as compared to typical window materials [72,78].…”

“…18, a) [72]. Synchrotron SAXS measurements were performed at the CHESS G1 Station, where X-ray beams had fluxes of 10 10 -10 12 photons/s at energies of 9.5 to 12 keV.…”

“…Thin Kapton films yield very little scattering and are typically used in protein solution SAXS [73]. However, an undoped 500 μm thick single-crystal CVD diamond grown in the atmosphere without intentional nitrogen addition had comparable SAXS signal to the background scattering of the direct beam, and showed even smaller or comparable scattering than a single 7.5 μm thick Kapton film, demonstrating that undoped single-crystal CVD diamond is an excellent window material for SAXS [72]. Comparison studies with a type Ia natural diamonds display more intense and/or anisotropic scattering as previously observed [74,75].…”

High pressure neutron and X-ray diffraction at low temperatures

“…2 for a comparison of their transmission properties with glass or sapphire. More recently, alternative low-Z (atomic number) materials such as chemicalvapour deposit diamonds (CVD) and cBN have been introduced as window materials due to their ability to withstand higher stresses with lower X-ray attenuation [86]. A further discussion of window materials and characteristics may be found elsewhere [87].…”

Synthetic diamond opens windows into the deep Earth

“…In addition to enhancing sample volume, large single-crystal diamonds can be fabricated for X-ray and neutron scattering measurements-both techniques require large samples [Wang et al, 2012]. Further, sensors and electrical circuits can be introduced to create smart designer anvils for electrical and thermal transport measurements [Samudrala et al, 2008].…”