Electron spin resonance, electron nuclear double resonance, and electron spin-echo spectroscopic studies of Argonne Premium Coals

Conference · Fri Dec 31 04:00:00 EST 1993

OSTI ID:441418

Chen, X; McManus, H; Kevan, L ^[1]

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1. Univ. of Houston, TX (United States)

Six coals provided by the Argonne Premium Coal Sample Program were studied by using electron spin resonance (ESR) and electron spin-echo (ESE) spectroscopy, and five of these coals were studied by using electron nuclear double resonance (ENDOR) spectroscopy. Measurements were conducted at various temperatures. Sample pretreatment was done by exposing to air, evacuating at room temperature, or evacuating at 673 K. Spin concentrations, g values, and relaxation parameters were all affected by the pretreatments. The average radius of the unpaired-electron wave function was determined from proton-matrix ENDOR results. ESE spectra show that {sup 13}C and {sup 1}H nuclei have significant interactions with the unpaired electrons in some coals. 19 refs., 4 figs., 3 tabs.

• OSTI ID: 441418
• Report Number(s): CONF-891206--
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
40 CHEMISTRY
AIR
BENCHMARKS
CARBON 13
COAL
ELECTRON SPIN RESONANCE
ELECTRONS
ENDOR
G VALUE
HYDROGEN
HYPERFINE STRUCTURE
MAGNETIC RESONANCE
RELAXATION TIME
SAMPLE PREPARATION
SPECTROSCOPY
SPIN ECHO