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

High-precision in situ isothermal measurements of 550 kHz shear modulus G of bulk glassy Pd40Cu30Ni10P20 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 τm = η / G calculated using independent G and shear viscosity η data. It has been concluded that τm may not serve as a universal time scale for different relaxation processes in supercooled liquid and glassy states.