Ferromagnetic contamination of ultra-low-field-NMR sample containers. Quantification of the problem and possible solutions

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:514

Article

Bevilacqua, Giuseppe¹  Biancalana, Valerio¹  Consumi, Marco²  Dancheva, Yordanka^3,4  Rossi, Claudio²  Stiaccini, Leonardo³  Vigilante, Antonio^1,5 

[1] Univ Siena, Dept Informat Engn & Math DIISM, Via Roma 56, I-53100 Siena, Italy

[2] Univ Siena, Dept Biotechnol Chem & Pharm DBCF, Via A Moro 2, I-53100 Siena, Italy

[3] Univ Siena, Dept Phys Sci Earth & Environm DSFTA, Via Roma 56, I-53100 Siena, Italy

[4] Aerosp Tecnol Srl, Str Ficaiole, I-53040 Rapolano Terme, SI, Italy

[5] UCL, Dept Phys & Astron, Gower St, London WC1E 6BT, England

关键词: Magnetic contamination;    Volume/surface ferromagnetic contamination;    Ultra-low-field NMR;    Ultra-low-field MRI;    Sample containers;    Optical magnetometry;    Chemical mapping;   

DOI  :  10.1016/j.jmmm.2020.167220

来源: Elsevier

【 摘 要 】

The presence of a weak remanence in Ultra-Low-Field (ULF) NMR sample containers is investigated on the basis of proton precession. The high-sensitivity magnetometer used for the NMR detection, enables simultaneously the measurement of the static field produced in the sample proximity by ferromagnetic contaminants. The presence of the latter is studied by high resolution chemical analyses of the surface, based on X-ray fluorescence spectroscopy and secondary ions mass spectroscopy. Methodologies to reduce the contamination are explored and characterized. This study is of relevance in any ULF-NMR experiment, as in the ULF regime spurious ferromagnetism becomes easily a dominant cause of artefacts.

【 授权许可】

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