Observation of secondary relaxation in a fragile Pd40Ni10Cu30P20 bulk metallic glass

The dynamic elastic moduli in the temperature domain of a Pd40Ni10Cu30P20 bulk metallic glass were measured with dynamic mechanical spectroscopy at frequencies less than 100 Hz. The primary relaxation is characterized by a single loss modulus peak and a rapid drop of storage modulus in the metallic supercooled liquid region. Below the conventional glass transition temperature, a pronounced shoulder in the loss modulus curves appears and the corresponding storage modulus decreases with increasing temperature. The phenomenon is common to glass formers of all types. The observations present the evidence of the existence of the slow beta relaxation and affirm the universality of the separation of the primary and secondary relaxations in the supercooled liquid. (c) 2006 American Institute of Physics.