NMR investigation of boron impurities in refined metallurgical grade silicon
- The nuclear magnetic resonance (NMR) method was applied for tracking boron impurities in the refining process of metallurgical grade (MG) silicon. From the NMR signal of the 11B isotope at an operating temperature 4.2 K, the boron concentration can be estimated down to the order of 110 wppm B. After melting and resolidification of MG-Si alloyed with Ca and Ti, a major fraction of B impurities remains in the Si solid solution as inferred from the characteristic NMR frequency. The alloying element Ti does not form substantial fractions of TiB2. Acid leaching of crushed powders of MG-Si alloyed with Ca and Ti can diminish the initial impurity content of B suggesting its accumulation in the grain boundary phases.
Author: | Hans-Joachim GrafeORCiD, Wolfgang Löser, Steffen Schmitz, Miroslava Sakaliyska, Sabine Wurmehl, Stefan Eisert, Birk Reichenbach, Jörg AckerORCiDGND, Anja RietigORCiD, Jana Ducke |
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URL: | http://onlinelibrary.wiley.com/doi/10.1002/pssa.201431908/full |
DOI: | https://doi.org/10.1002/pssa.201431908 |
ISSN: | 1862-6319 |
Title of the source (English): | Physica status solidi. A, Applications and Materials Science |
Document Type: | Scientific journal article peer-reviewed |
Language: | English |
Year of publication: | 2015 |
Tag: | Si-Al melt; boron; impurity; intermetallic compounds; nuclear magnetic resonance; removal; silicon; solidification; transition-metal diboride |
Volume/Year: | 212 |
Issue number: | 9 |
First Page: | 2031 |
Last Page: | 2036 |
Faculty/Chair: | Fakultät 2 Umwelt und Naturwissenschaften / FG Physikalische Chemie |