Density power law and structures of metallic glasses

Abstract The existence of a universal power law relating the position of the first sharp diffraction peak ( q , FSDP) to the density ( ρ or the volume V ) with a constant exponent P-q relationship does not necessary correspond to the P V equation of state of the bulk material and is not always a suitable indicator for monitoring structural phase transitions or volume changes. On the other hand, for suitable systems, neutron diffraction is a reliable method to determine the structural features of both heavy and light atoms. In this study, the simulated neutron diffraction patterns of Ca 72·7 Al 27.3 metallic glasses show a clear splitting of the FSDP at the pressure where the pressure-induced polyamorphism transition occurs. From the presented results, there is no justification for expecting the existence of a universal power scaling law with a constant exponent for all glasses.