Electron spin resonance in glassy carbon

✍ Scribed by S. Orzeszko; K.T. Yang

• Publisher: Elsevier Science
• Year: 1974
• Tongue: English
• Weight: 480 KB
• Volume: 12
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(74)90049-9

✦ Synopsis

The ESR was investigated for a series of samples of glassy carbon hear-treated to various temperatures in the range 10~~30~5C using a Q and X band spectrometers. For the sotid material, the width first increases slightly, then goes through a rninil~u~~~ at around 1400°C and increases greatly above HTT 2600°C. For a ground material, a iarge broadening in the transition range (-1300°C) is observed. The intensity for all samples passes through a minimum at HTT 1200°C and increases ta a strong maximum at around HTT 1550°C after which it decays to a value 0.5 x 10'" spin/g. The influence of neutron irradiation and of subsequent anneal are also reported. The irradiated material shows a large broadening in the transition range (-1300°C) similar to the broadening observed for irradiated soft carbons. Temperature dependence measurements of the ESR signal were carried out for nonirradiated and for irradiated samples, in order to determine the contribution of the localized spin and of the conduction carriers to the total intensitv.