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Local Electronic Structure in AlN Studied by Single-Crystal ²⁷Al and ¹⁴N NMR and DFT Calculations

Zeman, Otto E. O.; Moudrakovski, Igor L.; Hartmann, Carsten; Indris, Sylvio; Bräuniger, Thomas

Abstract (englisch):
Both the chemical shift and quadrupole coupling tensors for 14 N and 27 Al in the wurtzite structure of aluminum nitride have been determined to high precision by single-crystal NMR spectroscopy. A homoepitaxially grown AlN single crystal with known morphology was used, which allowed for optical alignment of the crystal on the goniometer axis. From the analysis of the rotation patterns of 14 N ( I=1 ) and 27 Al ( I=5/2 ), the quadrupolar coupling constants were determined to χ(14N)=(8.19±0.02) kHz, and χ(27Al)=(1.914±0.001) MHz. The chemical shift parameters obtained from the data fit were δiso=−(292.6±0.6) ppm and δΔ=−(1.9±1.1) ppm for 14 N, and (after correcting for the second-order quadrupolar shift) δiso=(113.6±0.3) ppm and δΔ=(12.7±0.6) ppm for 27 Al. DFT calculations of the NMR parameters for non-optimized crystal geometries of AlN generally did not match the experimental values, whereas optimized geometries came close for 27 Al with χ¯¯calc=(1.791±0.003) MHz, but not for 14 N with χ¯¯calc=−(19.5±3.3) kHz.

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Verlagsausgabe §
DOI: 10.5445/IR/1000105412
Veröffentlicht am 28.01.2020
DOI: 10.3390/molecules25030469
Zitationen: 1
Web of Science
Zitationen: 2
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Angewandte Materialien - Energiespeichersysteme (IAM-ESS)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2020
Sprache Englisch
Identifikator ISSN: 1420-3049
KITopen-ID: 1000105412
HGF-Programm 37.01.01 (POF III, LK 01)
Fundamentals and Materials
Erschienen in Molecules
Band 25
Heft 3
Seiten Article No.469
Vorab online veröffentlicht am 22.01.2020
Schlagwörter AlN; single-crystal NMR; 14N NMR; 27Al NMR; chemical shift tensor; quadrupole coupling tensor
Nachgewiesen in Scopus
Web of Science
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