Visualizing skin effects in conductors with MRI: 7Li MRI experiments and calculations

Andrew J. Ilott, S. Chandrashekar, Andreas Klöckner, Hee Jung Chang, Nicole M. Trease, Clare P. Grey, Leslie Greengard, Alexej Jerschow

Research output: Contribution to journalArticle

Abstract

While experiments on metals have been performed since the early days of NMR (and DNP), the use of bulk metal is normally avoided. Instead, often powders have been used in combination with low fields, so that skin depth effects could be neglected. Another complicating factor of acquiring NMR spectra or MRI images of bulk metal is the strong signal dependence on the orientation between the sample and the radio frequency (rf) coil, leading to non-intuitive image distortions and inaccurate quantification. Such factors are particularly important for NMR and MRI of batteries and other electrochemical devices. Here, we show results from a systematic study combining rf field calculations with experimental MRI of 7Li metal to visualize skin depth effects directly and to analyze the rf field orientation effect on MRI of bulk metal. It is shown that a certain degree of selectivity can be achieved for particular faces of the metal, simply based on the orientation of the sample. By combining rf field calculations with bulk magnetic susceptibility calculations accurate NMR spectra can be obtained from first principles. Such analyses will become valuable in many applications involving battery systems, but also metals, in general.

Original languageEnglish (US)
Pages (from-to)143-149
Number of pages7
JournalJournal of Magnetic Resonance
Volume245
DOIs
StatePublished - Aug 2014

Keywords

  • Lithium batteries
  • Magnetic resonance imaging
  • Rf field calculations
  • Skin effect
  • Susceptibility effects

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Nuclear and High Energy Physics
  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'Visualizing skin effects in conductors with MRI: <sup>7</sup>Li MRI experiments and calculations'. Together they form a unique fingerprint.

  • Cite this