Determination of the fraction of paramagnetic centers not-fulfilling the Curie law in coal macerals by the two-temperature EPR measurement method

Nukleonika

Więckowski Andrzej B.¹  Słowik Grzegorz P.² 

[1] Institute of Physics, Faculty of Physics and Astronomy, University of Zielona Góra, 4a Szafrana Str., 65-516 Zielona Góra, Poland and Institute of Molecular Physics of the Polish Academy of Sciences, 17 Smoluchowskiego Str., 60-179 Poznań, Poland;Institute of Physics, Faculty of Physics and Astronomy, University of Zielona Góra, 4a Szafrana Str., 65-516 Zielona Góra, Poland;

关键词: electron paramagnetic resonance (epr);    macerals;    two-temperature epr measurement;   

DOI  :  10.1515/nuka-2015-0069

来源: DOAJ

【 摘 要 】

Two-temperature electron paramagnetic resonance (EPR) measurements, applied to determine the relative contributions of paramagnetic centers – fulfilling and not-fulfilling the Curie law, were carried out. The measurements were made on the macerals – exinite and vitrinite, separated from clarain of the Polish medium-rank coal (85.6 wt% C). The two-temperature EPR measurements, presented in this work, were performed respectively, at temperatures: T1 = 293 K and T2 = 173 K for exinite, and T1 = 293 K and T2 = 153 K for vitrinite. The relative contributions X of spins not-fulfilling the Curie law present in the studied macerals were calculated. A comparison of different methods of calculating the relative contributions of paramagnetic centers – fulfilling and not-fulfilling the Curie law, present in exinite and vitrinite studied by EPR was made.

【 授权许可】

Unknown