Evaluation of energy band parameters of carbons

✍ Scribed by Tadamasa Kimura; Kazuhiko Yazawa

• Publisher: Elsevier Science
• Year: 1973
• Tongue: English
• Weight: 1022 KB
• Volume: 11
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(73)90064-x

✦ Synopsis

The systematic dependence of the Hall effect of carbons on the electronic band parameters has anaIyti~lly been studied on the basis of Yazawa's band model which takes into account in a simple way the interlayer perturbation. Many experimental results on the magnetic-field dependence of the Hall effect of carbons can be satisfactorily explained by adjusting the band parameters. The change in the Hall voltage with the band parameters is so drastic as to provide a powerful tool for evaluating these parameters of carbons. The evaluation procedures are described in detail and some examples of the application to experimental results presented. It is concluded that asdeposited pyrolytic graphite has a high concentration of acceptors with small activation energy (-lOmeV), which may probably originate from the structural defects. On the other hand, the activation energy of boron in graphite is found to exceed 100 me/'.