Identification of a Frenkel-pair defect in electron-irradiated 3C SiC
2009 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 80, 125201- p.Article in journal (Refereed) Published
Anelectron paramagnetic resonance (EPR) spectrum labeled LE1 was observed inn-type 3C SiC after electron irradiation at low temperatures (~80–100 K).A hyperfine interaction with four nearest C neighbors similar tothat of the well-known silicon vacancy in the negative chargestate was observed, but the LE1 center has a lowersymmetry, C2v. Supercell calculations of different configurations of silicon vacancy-interstitialFrenkel-pairs, VSi-Sii, were performed showing that pairs with a nearestneighbor Si interstitial are unstable—VSi and Sii will automatically recombine—whereaspairs with a second neighbor Sii are stable. Comparing thedata obtained from EPR and supercell calculations, the LE1 centeris assigned to the Frenkel-pair between VSi and a secondneighbor Sii interstitial along the  direction in the 3+charge state, V-Si. In addition, a path for the migrationof Si was found in 3C SiC. In samples irradiatedat low temperatures, the LE1 Frenkel-pair was found to bethe dominating defect whereas EPR signals of single vacancies werenot detected. The center disappears after warming up the samplesto room temperature.
Place, publisher, year, edition, pages
2009. Vol. 80, 125201- p.
electron beam effects, Frenkel defects, hyperfine interactions, interstitials, paramagnetic resonance, silicon compounds, wide band gap semiconductors
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:liu:diva-50688DOI: 10.1103/PhysRevB.80.125201OAI: oai:DiVA.org:liu-50688DiVA: diva2:271920