Electron-spin echoes and saturation in coal

✍ Scribed by Utpal Das; David C. Doetschman; Paul M. Jones; Lee Myung

• Publisher: Elsevier Science
• Year: 1983
• Tongue: English
• Weight: 405 KB
• Volume: 62
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(83)90083-2

✦ Synopsis

Free radical electron paramagnetic resonance (e.p.r.) spectra of coal are comprised of unresolved hyperfine multiplets with widths of ~770 kHz, (TJ', at 90-l 10 K. Unresolved hyperfine interactions are measured in the spin echo decay modulation and locate nuclei in the coal structure relative to the radical. With two distinguishable coal e.p.r. spectra in the sample, it is demonstrated that components may be separated from one another in the spin echo spectrum by judicious choice of temperature, pulse interval and echo repetition rate. The relaxation times T, and T2 are measured with the spin echo at several temperatures.