title: XPS and AFM studies of monodispersed Pb/PbO core-shell nanostructures.
abstract: A probe of the core-shell formation and the interfacial properties of monodispersed 30 nm Pb nanoparticles are presented. A direct correlation between the structures of the particle to its chemical states is done, by a careful Ar+ ion depth profiling followed by X-ray Photoelectron Spectroscopy and Atomic Force Microscopy. The study provides a unique insight into the structure of the nanoparticles. A PbO shell of 4 nm is observed to cover a 15-nm core, with a 5 nm interfacial region. The valence band spectra show the movement of the valence band maxima towards and beyond the Fermi-level during the insulator to metal transition along the particle depth. Evidence is also provided for an enhanced preferential sputtering of the PbO shell and an ion induced penetration of PbO into the Pb core.
authors.affiliation: Thin Film Laboratory, Department of Physics, Indian Institute of Technology, New Delhi 110016, India.
authors.forename: Manika
authors.initials: M
authors.lastname: Khanuja
authors.forename: Shubhra
authors.initials: S
authors.lastname: Kala
authors.forename: B R
authors.initials: BR
authors.lastname: Mehta
authors.forename: Himani
authors.initials: H
authors.lastname: Sharma
authors.forename: S M
authors.initials: SM
authors.lastname: Shivaprasad
authors.forename: B
authors.initials: B
authors.lastname: Balamurgan
authors.forename: A
authors.initials: A
authors.lastname: Maisels
authors.forename: F E
authors.initials: FE
authors.lastname: Kruis
mesh_terms: D003102:Colloids / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D007854:Lead / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010087:Oxides / Q000737:chemistry*; D010316:Particle Size; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties
chemical_list: D003102:Colloids; D046911:Macromolecular Substances; D010087:Oxides; D007854:Lead; C047365:lead oxide