title: Universal fractional noncubic power law for density of metallic glasses.
abstract: As a fundamental property of a material, density is controlled by the interatomic distances and the packing of microscopic constituents. The most prominent atomistic feature in a metallic glass (MG) that can be measured is its principal diffraction peak position (q1) observable by x-ray, electron, or neutron diffraction, which is closely associated with the average interatomic distance in the first shell. Density (and volume) would naturally be expected to vary under compression in proportion to the cube of the one-dimensional interatomic distance. However, by using high pressure as a clean tuning parameter and high-resolution in situ techniques developed specifically for probing the density of amorphous materials, we surprisingly found that the density of a MG varies with the 5/2 power of q1, instead of the expected cubic relationship. Further studies of MGs of different compositions repeatedly produced the same fractional power law of 5/2 in all three MGs we investigated, suggesting a universal feature in MG.
authors.affiliation: Geological and Environmental Sciences, Stanford University, Stanford, California 94305, USA and Photon Science and Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA and HPSynC, Geophysical Laboratory, Carnegie Institution of Washington, 9700 South Cass Avenue, Argonne, Illinois 60439, USA and Center for High Pressure Science and Technology Advanced Research (HPSTAR), 1690 Cailun Road, Pudong, Shanghai 201203, People's Republic of China.
authors.forename: Qiaoshi
authors.initials: Q
authors.lastname: Zeng
authors.affiliation: HPCAT, Geophysical Laboratory, Carnegie Institution of Washington, 9700 South Cass Avenue, Argonne, Illinois 60439, USA.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kono
authors.affiliation: Geological and Environmental Sciences, Stanford University, Stanford, California 94305, USA.
authors.forename: Yu
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Geological and Environmental Sciences, Stanford University, Stanford, California 94305, USA and Photon Science and Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA and HPSynC, Geophysical Laboratory, Carnegie Institution of Washington, 9700 South Cass Avenue, Argonne, Illinois 60439, USA and Center for High Pressure Science and Technology Advanced Research (HPSTAR), 1690 Cailun Road, Pudong, Shanghai 201203, People's Republic of China.
authors.forename: Zhidan
authors.initials: Z
authors.lastname: Zeng
authors.affiliation: HPSynC, Geophysical Laboratory, Carnegie Institution of Washington, 9700 South Cass Avenue, Argonne, Illinois 60439, USA and Center for High Pressure Science and Technology Advanced Research (HPSTAR), 1690 Cailun Road, Pudong, Shanghai 201203, People's Republic of China.
authors.forename: Junyue
authors.initials: J
authors.lastname: Wang
authors.affiliation: HPCAT, Geophysical Laboratory, Carnegie Institution of Washington, 9700 South Cass Avenue, Argonne, Illinois 60439, USA.
authors.forename: Stanislav V
authors.initials: SV
authors.lastname: Sinogeikin
authors.affiliation: HPCAT, Geophysical Laboratory, Carnegie Institution of Washington, 9700 South Cass Avenue, Argonne, Illinois 60439, USA.
authors.forename: Changyong
authors.initials: C
authors.lastname: Park
authors.affiliation: HPCAT, Geophysical Laboratory, Carnegie Institution of Washington, 9700 South Cass Avenue, Argonne, Illinois 60439, USA.
authors.forename: Yue
authors.initials: Y
authors.lastname: Meng
authors.affiliation: HPSynC, Geophysical Laboratory, Carnegie Institution of Washington, 9700 South Cass Avenue, Argonne, Illinois 60439, USA and Center for High Pressure Science and Technology Advanced Research (HPSTAR), 1690 Cailun Road, Pudong, Shanghai 201203, People's Republic of China.
authors.forename: Wenge
authors.initials: W
authors.lastname: Yang
authors.affiliation: HPSynC, Geophysical Laboratory, Carnegie Institution of Washington, 9700 South Cass Avenue, Argonne, Illinois 60439, USA and Center for High Pressure Science and Technology Advanced Research (HPSTAR), 1690 Cailun Road, Pudong, Shanghai 201203, People's Republic of China.
authors.forename: Ho-Kwang
authors.initials: HK
authors.lastname: Mao
authors.affiliation: Geological and Environmental Sciences, Stanford University, Stanford, California 94305, USA and Photon Science and Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
authors.forename: Wendy L
authors.initials: WL
authors.lastname: Mao