Merging of the α and β relaxations and aging via the Johari-Goldstein modes in rapidly quenched metallic glasses

• Published in: Applied physics letters Vol. 92; no. 13; pp. 131911 - 131911-3
• Main Authors: Hachenberg, Jörg, Bedorf, Dennis, Samwer, Konrad, Richert, Ranko, Kahl, Annelen, Demetriou, Marios D., Johnson, William L.
• Format: Journal Article
• Language: English
• Published: American Institute of Physics 31-03-2008
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.2903697

This paper provides evidence that the physical aging of deeply and rapidly quenched metallic glasses is promoted by the Johari-Goldstein slow
β
relaxation, resulting in a significant irreversible increase in the mechanical modulus on initial heating. Dynamic mechanical analysis has been used to characterize relaxation phenomena of a strong and a fragile metallic glass. In addition, we can extrapolate the temperature dependence of
β
- and
α
-relaxation peaks to higher temperatures and calculate the merging temperature for both types of glasses.