On the case of the negative activation volumes of defects in solids

✍ Scribed by G.E. Zardas; Ch.I. Symeonides

• Book ID: 103887212
• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 137 KB
• Volume: 404
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2008.12.029

✦ Synopsis

When conductivity, self-diffusion or electrical relaxation measurements are carried out at various pressures, the results are described in terms of a defect activation volume. Here, we discuss the rare case of negative activation volumes e.g., the one found by Fontanella et al. [Phys. Rev. Lett. 51 (1983) 1992] in the electrical relaxation measurements under pressure in b-PbF 2 doped with lanthanum and cerium.

This might be of importance for the explanation of electric signals detected before earthquakes, We suggest that this might be due to a small Gruneisen constant g i , namely smaller than 1 3 .