title: Bubble nucleation and migration in a lead-iron hydr(oxide) core-shell nanoparticle.
abstract: Iron hydroxide is found in a wide range of contexts ranging from biominerals to steel corrosion, and it can transform to anhydrous oxide via releasing O2 gas and H2O. However, it is not well understood how gases transport through a crystal lattice. Here, we present in situ observation of the nucleation and migration of gas bubbles in iron (hydr)oxide using transmission electron microscopy. We create Pb-FeOOH model core-shell nanoparticles in a liquid cell. Under electron irradiation, iron hydroxide transforms to iron oxide, during which bubbles are generated, and they migrate through the shell to the nanoparticle surface. Geometric phase analysis of the shell lattice shows an inhomogeneous stain field at the bubbles. Our modeling suggests that the elastic interaction between the core and the bubble provides a driving force for bubble migration.
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720;
authors.forename: Kaiyang
authors.identifier: http://orcid.org/0000-0003-3289-1322
authors.initials: K
authors.lastname: Niu
authors.affiliation: Department of Materials Science and Engineering, University of California, Berkeley, CA 94720;
authors.forename: Timofey
authors.initials: T
authors.lastname: Frolov
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720;
authors.forename: Huolin L
authors.initials: HL
authors.lastname: Xin
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798.
authors.forename: Junling
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Materials Science and Engineering, University of California, Berkeley, CA 94720;
authors.forename: Mark
authors.initials: M
authors.lastname: Asta
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720; Department of Materials Science and Engineering, University of California, Berkeley, CA 94720; hmzheng@lbl.gov.
authors.forename: Haimei
authors.initials: H
authors.lastname: Zheng
keywords: TEM; bubbles; core–shell nanoparticle; liquid cell; nucleation