title: Applications and limitations of electron correlation microscopy to study relaxation dynamics in supercooled liquids.
abstract: Electron correlation microscopy (ECM) is a way to measure structural relaxation times, τ, of liquids with nanometer-scale spatial resolution using coherent electron scattering equivalent of photon correlation spectroscopy. We have applied ECM with a 3.5nm diameter probe to Pt57.5Cu14.7Ni5.3P22.5amorphous nanorods and Pd40Ni40P20bulk metallic glass (BMG) heated inside the STEM into the supercooled liquid region. These data demonstrate that the ECM technique is limited by the characteristics of the time series, which must be at least 40τ to obtain a well-converged correlation function g2(t), and the time per frame, which must be less than 0.1τ to obtain sufficient sampling. A high-speed direct electron camera enables fast acquisition and affords reliable g2(t) data even with low signal per frame.
authors.affiliation: Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA.
authors.forename: Pei
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA.
authors.forename: Li
authors.initials: L
authors.lastname: He
authors.affiliation: Materials Science and Engineering, Ames Laboratory, Iowa State University, Ames, IA 50011, USA.
authors.forename: Matthew F
authors.initials: MF
authors.lastname: Besser
authors.affiliation: Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT 06511, USA.
authors.forename: Ze
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT 06511, USA.
authors.forename: Jan
authors.initials: J
authors.lastname: Schroers
authors.affiliation: Materials Science and Engineering, Ames Laboratory, Iowa State University, Ames, IA 50011, USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Kramer
authors.affiliation: Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA. Electronic address: paul.voyles@wisc.edu.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Voyles
keywords: Electron correlation microscopy; In-situ heating; Metallic glass; Structural relaxation time; Supercooled liquid