Angstrom-scale probing of paramagnetic centers location in nanodiamonds by 3He NMR at low temperatures
| Autor: | Gleb Dolgorukov, V. V. Kuzmin, Sergei Orlinskii, E. M. Alakshin, M. S. Tagirov, K. R. Safiullin, B. V. Yavkin, Andrey Stanislavovas, Mikhail Yu. Presnyakov, Airat Kiiamov, T. R. Safin, A. V. Klochkov |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Shell (structure) General Physics and Astronomy chemistry.chemical_element 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Molecular physics law.invention Magnetic field Paramagnetism Adsorption chemistry law 0103 physical sciences Condensed Matter::Strongly Correlated Electrons Angstrom Physical and Theoretical Chemistry 010306 general physics 0210 nano-technology Electron paramagnetic resonance Nanodiamond Carbon |
| Zdroj: | Physical Chemistry Chemical Physics. 20:1476-1484 |
| ISSN: | 1463-9084 1463-9076 |
| Popis: | In this article a method to assess the location of paramagnetic centers in nanodiamonds was proposed. The nuclear magnetic relaxation of adsorbed 3He used as a probe in this method was studied at temperatures of 1.5–4.2 K and magnetic fields of 100–600 mT. A strong influence of the paramagnetic centers of the sample on the 3He nuclear spin relaxation time T1 was found. Preplating the nanodiamond surface with adsorbed nitrogen layers allowed us to vary the distance from 3He nuclei to paramagnetic centers in a controlled way and to determine their location using a simple model. The observed T1 minima in temperature dependences are well described within the frame of the suggested model and consistent with the concentration of paramagnetic centers determined by electron paramagnetic resonance. The average distance found from the paramagnetic centers to the nanodiamond surface (0.5 ± 0.1 nm) confirms the well-known statement that paramagnetic centers in this type of nanodiamond are located in the carbon shell. The proposed method can be applied to detailed studies of nano-materials at low temperatures. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|