title: Hidden amorphous phase and reentrant supercooled liquid in Pd-Ni-P metallic glasses.
abstract: An anomaly in differential scanning calorimetry has been reported in a number of metallic glass materials in which a broad exothermal peak was observed between the glass and crystallization temperatures. The mystery surrounding this calorimetric anomaly is epitomized by four decades long studies of Pd-Ni-P metallic glasses, arguably the best glass-forming alloys. Here we show, using a suite of in situ experimental techniques, that Pd-Ni-P alloys have a hidden amorphous phase in the supercooled liquid region. The anomalous exothermal peak is the consequence of a polyamorphous phase transition between two supercooled liquids, involving a change in the packing of atomic clusters over medium-range length scales as large as 18 Å. With further temperature increase, the alloy reenters the supercooled liquid phase, which forms the room-temperature glass phase on quenching. The outcome of this study raises a possibility to manipulate the structure and hence the stability of metallic glasses through heat treatment.
authors.affiliation: Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology, 200 Xiaolingwei Avenue, Nanjing 210094, China.|Department of Physics and Materials Science, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, China.
authors.forename: S
authors.initials: S
authors.lastname: Lan
authors.affiliation: X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Ren
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, China.
authors.forename: X Y
authors.initials: XY
authors.lastname: Wei
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, China.
authors.forename: B
authors.initials: B
authors.lastname: Wang
authors.affiliation: Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organization (ANSTO), Locked Bag 2001, Kirrawee DC NSW 2232, Australia.
authors.forename: E P
authors.initials: EP
authors.lastname: Gilbert
authors.affiliation: Laboratory of Quantum Beam System, Division of Quantum Beam Engineering, Faculty of Engineering, Hokkaido University, Kita 13, Nishi 8, Sapporo 060-8628, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Shibayama
authors.affiliation: Laboratory of Quantum Beam System, Division of Quantum Beam Engineering, Faculty of Engineering, Hokkaido University, Kita 13, Nishi 8, Sapporo 060-8628, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Watanabe
authors.affiliation: Laboratory of Quantum Beam System, Division of Quantum Beam Engineering, Faculty of Engineering, Hokkaido University, Kita 13, Nishi 8, Sapporo 060-8628, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Ohnuma
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, China.|City University of Hong Kong Shenzhen Research Institute, 8 Yuexing 1st Road, Shenzhen Hi-Tech Industrial Park, Shenzhen 518057, China.|Center for Advanced Structural Materials, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, China.
authors.forename: X-L
authors.initials: XL
authors.lastname: Wang