X-ray diffraction study of the structure of detonation nanodiamonds

In this paper we propose a method for ultrafine fractionation of nanodiamonds using the differential centrifugation in the fields up to 215000g. The developed protocols yield 4-6 nm fraction giving main contribution to the light scattering intensity. The desired 4-6 nm fraction can be obtained from various types of initial nanodiamonds: three types of detonation nanodiamonds differing in purifying methods, laser synthesis nanodiamonds and nanodiamonds made by milling. The characterization of the obtained hydrosols was conducted with Dynamic Light Scattering, Zeta potential measurements, powder XRD and TEM. According to powder XRD and TEM data ultracentrifugation also leads to a further fractionation of the primary diamond nanocrystallites in the hydrosols from 4 to 2 nm.

show abstract

“…6 , sample DND-asrec) and with typical profiles in Ref. 10 . Also it resembles the XRD data from Ref.…”

Section: B Characterization Of Nanodiamonds After Ultracentrifugationmentioning

confidence: 99%

Ultracentrifugation for ultrafine nanodiamond fractionation

Koniakhin

Besedina

Kirilenko

et al. 2018

Superlattices and Microstructures

View full text Add to dashboard Cite

show abstract

“…[19]. Comparison of the theoretical curves, calculated with formulae (11,12) and the experimental data for the considered materials are presented in Fig. 2.…”

Section: Mainmentioning

confidence: 99%

“…For instance, the size of detonation nanodiamonds was determined by small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) [11], dynamic light scattering (DLS) [12] and was acquired by computer simulations [13]. We compare sizes determined by other methods with those determined by Raman scattering data analyzed with present formula.…”

Section: Mainmentioning

confidence: 99%

New explanation of Raman peak redshift in nanoparticles

Meilakhs

Koniakhin

2017

Superlattices and Microstructures

View full text Add to dashboard Cite

In this letter, we propose a new model that explains the Raman peak downshift observed in nanoparticles with respect to bulk materials. The proposed model takes into account discreteness of the vibrational spectra of nanoparticles. For crystals with a cubic lattice (Diamond, Silicon, Germanium) we give a relation between the displacement of Raman peak position and the size of nanoparticles. The proposed model does not include any uncertain parameters, unlike the conventionally used phonon confinement model (PCM), and can be employed for unambiguous nanoparticles size estimation. MainIn nanoparticles the crystalline Raman peak position is downshifted and asymmetrically broadened with respect to bulk materials. Previously the * kon@mail.ioffe.ru 1 arXiv:1602.00114v1 [cond-mat.mes-hall]

show abstract

“…This value has been obtained using X-ray scattering and TEM data (Ozerin et al 2008), processing of the Raman scattering…”

Section: Methodsmentioning

confidence: 99%