EPR and double resonances in study of diamonds and nanodiamonds

Yavkin, Boris; Gafurov, Marat; Volodin, M. A.; Mamin, G. V.; Orlinskiĭ, S. B.

doi:10.1016/b978-0-12-814024-6.00005-4

Cited by 4 publications

(5 citation statements)

References 62 publications

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“…Figure plots the single-integrated EPR spectra of dry, H-terminated nanodiamond both with and without a prior annealing in air. Because diamond has several bulk and surface defects that are EPR-active, there are several peaks that arise from the diamond itself. , The three most abundant defects of nanodiamond this size are the substitutional nitrogen defects (P1 centers) and two surface carbon defects (frequently denoted SC1/SC2 or “X” in the literature) that are unique to nanodiamonds. , These surface defects have been attributed to negatively charged vacancy defects, “dangling bonds” in sp 2 -hybridized carbon, and structural defects. − These two surface defects appear as only one peak at the X-band frequencies used here . In Figure , black arrows mark the location of the bulk P1 centers and the combined “surface defect” signal.…”

Section: Resultsmentioning

confidence: 99%

“…We also include a no-EDC control sample prepared identically except that no EDC was present to cross-link the TEMPO to the diamond surface during the functionalization step. While EPR spectra are typically acquired in derivative mode, single integration of the EPR signal yields peaks, while double integration yields the total spin signal from each sample . To facilitate analysis of the spectra, we normalized the intensities of the spectra in Figure such that each spectrum has the same total double-integrated peak area …”

Section: Resultsmentioning

confidence: 99%

“…While EPR spectra are typically acquired in derivative mode, single integration of the EPR signal yields peaks, while double integration yields the total spin signal from each sample . To facilitate analysis of the spectra, we normalized the intensities of the spectra in Figure such that each spectrum has the same total double-integrated peak area Figure shows the EPR spectrum of TEMPO-ND in dry form; the three peaks corresponding to the spin of aminoxyl radicals anisotropically oriented along the applied magnetic field and showing the greatest spectral width are denoted by the blue arrows. , Upon the addition of a small amount of water to hydrate the sample, the peaks become more obvious, which we attribute to sharpening of the lines as a result of increased orientational averaging of the TEMPO molecules with greater rotational freedom.…”

Section: Resultsmentioning

confidence: 99%

“…Because diamond has several bulk and surface defects that are EPR-active, there are several peaks that arise from the diamond itself. 32,33 The three most abundant defects of nanodiamond this size are the substitutional nitrogen defects (P1 centers) and two surface carbon defects (frequently denoted SC1/SC2 or "X" in the literature) that are unique to nanodiamonds. 33,34 These surface defects have been attributed to negatively charged vacancy defects, "dangling bonds" in sp 2 -hybridized carbon, and structural defects.…”

Section: Dls and ζ-Potentialmentioning

confidence: 99%

“…32,33 The three most abundant defects of nanodiamond this size are the substitutional nitrogen defects (P1 centers) and two surface carbon defects (frequently denoted SC1/SC2 or "X" in the literature) that are unique to nanodiamonds. 33,34 These surface defects have been attributed to negatively charged vacancy defects, "dangling bonds" in sp 2 -hybridized carbon, and structural defects. 34−36 These two surface defects appear as only one peak at the X-band frequencies used here.…”

Section: Dls and ζ-Potentialmentioning

confidence: 99%

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High-Density Covalent Grafting of Spin-Active Molecular Moieties to Diamond Surfaces

et al. 2021

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Functionalization of diamond surfaces with TEMPO and other surface paramagnetic species represents one approach to the implementation of novel chemical detection schemes that make use of shallow quantum color defects such as silicon-vacancy (SiV) and nitrogen-vacancy (NV) centers. Yet, prior approaches to quantum-based chemical sensing have been hampered by the absence of high-quality surface functionalization schemes for linking radicals to diamond surfaces. Here, we demonstrate a highly controlled approach to the functionalization of diamond surfaces with carboxylic acid groups via all-carbon tethers of different lengths, followed by covalent chemistry to yield high-quality, TEMPO-modified surfaces. Our studies yield estimated surface densities of 4-amino-TEMPO of approximately 1.4 molecules nm −2 on nanodiamond (varying with molecular linker length) and 3.3 molecules nm −2 on planar diamond. These values are higher than those reported previously using other functionalization methods. The ζ-potential of nanodiamonds was used to track reaction progress and elucidate the regioselectivity of the reaction between ethenyl and carboxylate groups and surface radicals.

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