Measurements of slowβ-relaxations in metallic glasses and supercooled liquids

An explanation of the differences in diffusivity of the components of the metallic glass Pd43Cu27Ni10P20

“…Only in a rare case of ionic liquids [41], n D was known together with the coupling parameter of the structural relaxation n α or viscosity n η , and the qualitative explanation becomes rigorous. In the present case of Pd 43 Cu 27 Ni 10 P 20 , we are fortunate to have the results from the recent study by Yu et al [15], and from which we can deduce the coupling parameter n D of P. On the other hand, we can obtain n α or n η from the mechanical relaxation data of a closely related BGM, Pd 40 Ni 10 Cu 30 P 20 , [2].…”

“…If the value of the fractional exponent given by Eq. (8) [2]. They reported the value of 0.57 for the stretch exponent,…”

Structural origins of Johari-Goldstein relaxation in a metallic glass

“…JG relaxation is superimposed on the broad sub-T g exothermic relaxation patterns that are the direct outcome of combined secondary and primary relaxations, while JG relaxation appears at the low-temperature side as the tails of the primary relaxation bands 7,8,16 . It has been suggested that the relaxation of metallic glasses depends on fragility, cooling rate, chemical bonding, atomic size disparity and constitute atom diffusivity 3,8,9,[16][17][18][19] . Since these kinetic and chemical variables are essentially associated with structure of metallic glasses, directly investigating the correlation between atomic structure and JG relaxation may shed a light on the atomic origins of the lowtemperature relaxation.…”

Comparing the atomic and macroscopic aging dynamics in an amorphous and partially crystalline Zr44Ti11Ni10Cu10Be25bulk metallic glass

“…8,10 It should be noted that this temperature range also corresponds to that of the fast β-relaxation observed in DMA studies on a similar Zr46.25Ti8.25Cu7.5Ni10Be27.5 (Vitreloy 4) alloy. 36 Thus, the decrease in β observed in this temperature range might also be connected to the low-temperature onset of stress relaxation and excess free volume annihilation in the glassy state. 12 To investigate the changes to the atomic motion as a result of aging, we compare the waiting time-dependent dynamics in the partially crystallized sample close to Tg with that in the fully amorphous sample measured during step-heating from ambient temperature.…”