Studies of e.s.r. linewidths in coals and related materials

✍ Scribed by H.L. Retcofsky; Gordon P. Thompson; Raphael Raymond; Robert A. Friedel

• Publisher: Elsevier Science
• Year: 1975
• Tongue: English
• Weight: 403 KB
• Volume: 54
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(75)90068-x

✦ Synopsis

An investigation was carried out to explore the importance of two line-broadening mechanisms which may be responsible for the width of the electron spin resonance signals exhibited by coals. Studies of catalytically dehydrogenated coals, isotopically substituted low-temperature chars, and a large number of vitrains from coals of all ranks support the view that electron-nuclear hyperfine interactions produce significant contributions to the e.s.r. linewidths found for low-rank coals. Anisotropic g-values appear to be relatively unimportant for low-rank coals, but measurements made on oriented sections of young anthracitic coals revealed a small but reproducible anisotropy in the e.s.r. g tensor.