Identification of the neutral carbon 〈100〉-split interstitial in diamond

Autor: Daniel J. Twitchen, Thomas R. Anthony, M. E. Newton, Suresh Shankarappa Vagarali, William F. Banholzer, J. M. Baker, D.C. Hunt
Rok vydání: 2000
Předmět:
Zdroj: Physical Review B. 61:3863-3876
ISSN: 1095-3795
0163-1829
DOI: 10.1103/physrevb.61.3863
Popis: A systematic study has been made of some of the properties of R2, the most dominant paramagnetic defect produced in type-IIa diamond by electron irradiation. R2 has been produced in high-purity synthetic diamonds, which have been irradiated with 2 MeV electrons in a specially developed dewar, allowing irradiation down to a measured sample temperature of 100 K, at doses of $2\ifmmode\times\else\texttimes\fi{}{10}^{17}$ to $4\ifmmode\times\else\texttimes\fi{}{10}^{18}$ electrons ${\mathrm{cm}}^{\ensuremath{-}2}.$ The production rate of vacancies $[1.53(10){\mathrm{cm}}^{\ensuremath{-}1}]$ was the same for irradiation at 100 K as at 350 K, but the production rate of the R2 electron-paramagnetic-resonance (EPR) center is $1.1(1){\mathrm{cm}}^{\ensuremath{-}1}$ at 100 K and only $0.10(5){\mathrm{cm}}^{\ensuremath{-}1}$ at 350 K. Measurements have been made of the angular variation of the EPR linewidth, ${}^{13}\mathrm{C}$ hyperfine structure of samples grown with enriched isotopic abundance of ${}^{13}\mathrm{C},$ and of the EPR of samples annealed under uniaxial stress (for which a special equipment was developed). A combination of these data with the previously measured data has shown that R2 is the neutral $〈100〉$-split self-interstitial. This is an identification of an isolated stable self-interstitial in a group IV material. This shows that the self-interstitial is not mobile in type-IIa diamond under normal conditions (i.e., without the irradiation) until the annealing temperature of 700 K.
Databáze: OpenAIRE