Unexpectedly large relaxation time determined by in situ high-frequency shear modulus measurements near the glass transition of bulk glassy Pd40Cu30Ni10P20

Abstract High-precision in situ isothermal measurements of 550 kHz shear modulus G of bulk glassy Pd 40 Cu 30 Ni 10 P 20 slightly below and above the glass transition temperature have been performed. It has been found, contrary to the expectation, that the observed relaxation time exceeds by 20–45 times the Maxwell relaxation time τ m = η / G calculated using independent G and shear viscosity η data. It has been concluded that τ m may not serve as a universal time scale for different relaxation processes in supercooled liquid and glassy states.