title: Heterogeneity in the Small-Scale Deformation Behavior of Disordered Nanoparticle Packings.
abstract: Atomic force microscopy-based nanoindentation is used to image and probe the local mechanical properties of thin disordered nanoparticle packings. The probed region is limited to the size of a few particles, and an individual particle can be loaded and displaced to a fraction of a single particle radius. The results demonstrate heterogeneous mechanical response that is location-dependent. The weak locations may be analogous to the "soft spots" previously predicted in glasses and other disordered packings.
authors.affiliation: Department of Materials Science & Engineering, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Joel A
authors.initials: JA
authors.lastname: Lefever
authors.affiliation: Department of Materials Science & Engineering, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Tevis D B
authors.initials: TD
authors.lastname: Jacobs
authors.affiliation: Department of Mechanical Engineering & Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Qizhan
authors.initials: Q
authors.lastname: Tam
authors.affiliation: Department of Chemical & Biomolecular Engineering, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Jyo Lyn
authors.initials: JL
authors.lastname: Hor
authors.affiliation: Department of Chemical & Biomolecular Engineering, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Yun-Ru
authors.initials: YR
authors.lastname: Huang
authors.affiliation: Department of Chemical & Biomolecular Engineering, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Daeyeon
authors.initials: D
authors.lastname: Lee
authors.affiliation: Department of Mechanical Engineering & Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Carpick
keywords: Disordered nanoparticle packing; amorphous material; atomic force microscopy; nanoindentation; shear transformation zone; soft spot