Details
| Original language | English |
|---|---|
| Pages (from-to) | 2183-2192 |
| Number of pages | 10 |
| Journal | ACS Omega |
| Volume | 3 |
| Issue number | 2 |
| Publication status | Published - 2018 |
| Externally published | Yes |
Abstract
Microwave dielectric loss tangent measurements are demonstrated as a method for quantifying trace sp 2-hybridized carbon impurities in sub-micron diamond powders. Appropriate test samples are prepared by vacuum annealing at temperatures from 600 to 1200 °C to vary the sp 2/sp 3 carbon ratio through partial surface graphitization. Microwave permittivity measurements are compared with those obtained using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and electron energy loss spectroscopy (EELS). The average particle size remains constant (verified by scanning electron microscopy) to decouple any geometric dielectric effects from the microwave measurements. After annealing, a small increase in sp 2 carbon was identified from the XPS C 1s and Auger spectra, the EELS σ∗ peak in the C 1s spectra, and the D and G bands in Raman spectroscopy, although a quantifiable diamond to G-band peak ratio was unobtainable. Surface hydrogenation was also evidenced in the Raman and XPS O 1s data. Microwave cavity perturbation measurements show that the dielectric loss tangent increases with increasing sp 2 bonding, with the most pertinent finding being that these values correlate with other measurements and that trace concentrations of sp 2 carbon as small as 5% can be detected.
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: ACS Omega, Vol. 3, No. 2, 2018, p. 2183-2192.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Microwave Permittivity of Trace sp2 Carbon Impurities in Sub-Micron Diamond Powders
AU - Cuenca, J.A.
AU - Thomas, E.L.H.
AU - Mandal, S.
AU - Morgan, D.J.
AU - Lloret, F.
AU - Araujo, D.
AU - Williams, O.A.
AU - Porch, A.
N1 - Publisher Copyright: © 2018 American Chemical Society.
PY - 2018
Y1 - 2018
N2 - Microwave dielectric loss tangent measurements are demonstrated as a method for quantifying trace sp 2-hybridized carbon impurities in sub-micron diamond powders. Appropriate test samples are prepared by vacuum annealing at temperatures from 600 to 1200 °C to vary the sp 2/sp 3 carbon ratio through partial surface graphitization. Microwave permittivity measurements are compared with those obtained using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and electron energy loss spectroscopy (EELS). The average particle size remains constant (verified by scanning electron microscopy) to decouple any geometric dielectric effects from the microwave measurements. After annealing, a small increase in sp 2 carbon was identified from the XPS C 1s and Auger spectra, the EELS σ∗ peak in the C 1s spectra, and the D and G bands in Raman spectroscopy, although a quantifiable diamond to G-band peak ratio was unobtainable. Surface hydrogenation was also evidenced in the Raman and XPS O 1s data. Microwave cavity perturbation measurements show that the dielectric loss tangent increases with increasing sp 2 bonding, with the most pertinent finding being that these values correlate with other measurements and that trace concentrations of sp 2 carbon as small as 5% can be detected.
AB - Microwave dielectric loss tangent measurements are demonstrated as a method for quantifying trace sp 2-hybridized carbon impurities in sub-micron diamond powders. Appropriate test samples are prepared by vacuum annealing at temperatures from 600 to 1200 °C to vary the sp 2/sp 3 carbon ratio through partial surface graphitization. Microwave permittivity measurements are compared with those obtained using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and electron energy loss spectroscopy (EELS). The average particle size remains constant (verified by scanning electron microscopy) to decouple any geometric dielectric effects from the microwave measurements. After annealing, a small increase in sp 2 carbon was identified from the XPS C 1s and Auger spectra, the EELS σ∗ peak in the C 1s spectra, and the D and G bands in Raman spectroscopy, although a quantifiable diamond to G-band peak ratio was unobtainable. Surface hydrogenation was also evidenced in the Raman and XPS O 1s data. Microwave cavity perturbation measurements show that the dielectric loss tangent increases with increasing sp 2 bonding, with the most pertinent finding being that these values correlate with other measurements and that trace concentrations of sp 2 carbon as small as 5% can be detected.
UR - http://www.scopus.com/inward/record.url?scp=85054233106&partnerID=8YFLogxK
U2 - 10.1021/acsomega.7b02000
DO - 10.1021/acsomega.7b02000
M3 - Article
VL - 3
SP - 2183
EP - 2192
JO - ACS Omega
JF - ACS Omega
IS - 2
ER -