Macroscopic sample shape effect on pulse electron double resonance (PELDOR) signal

Vasyl Denysenkov; Thomas F Prisner; Petr Neugebauer; Stefan Stoll; Andriy Marko

doi:10.1016/j.jmr.2023.107564

Macroscopic sample shape effect on pulse electron double resonance (PELDOR) signal

J Magn Reson. 2023 Nov:356:107564. doi: 10.1016/j.jmr.2023.107564. Epub 2023 Oct 10.

Authors

Vasyl Denysenkov¹, Thomas F Prisner¹, Petr Neugebauer², Stefan Stoll³, Andriy Marko⁴

Affiliations

¹ Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance, Goethe University Frankfurt, Max-von-Laue Str. 7, 60437, Frankfurt am Main, Germany.
² Central European Institute of Technology and Brno University of Technology, Purkynova 123, Brno, 61200, Czech Republic.
³ Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195-1700, USA.
⁴ Central European Institute of Technology and Brno University of Technology, Purkynova 123, Brno, 61200, Czech Republic. Electronic address: Andriy.Marko@ceitec.vutbr.cz.

PMID: 37852111
DOI: 10.1016/j.jmr.2023.107564

Abstract

Pulse electron double resonance (PELDOR), also called double electron-electron resonance (DEER), is a technique capable of measuring the strength of electron spin dipolar interactions, revealing spin-spin distance distributions in ordered and disordered solid materials. Previous work has shown that PELDOR signals acquire an out-of-phase component under conditions of high electron spin polarization, such as at low temperatures and high fields. In this paper, we show theoretically and experimentally that the size and sign of this effect depends on the macroscopic shape of the sample and its orientation in the external magnetic field. This effect is caused by dipolar interactions between distant spins and provides new insights into the fundamental physics of PELDOR.

Keywords: DEER; EPR; High field; High polarization; Low temperatures; PELDOR.