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Comparative surface studies of oxygen passivated FeCo nanoparticles and thin films
Author(s) -
Jaffari G. Hassnain,
Lin H.,
Rumaiz A. K.,
Yassitepe Emre,
Ni C.,
Shah S. Ismat
Publication year - 2013
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201228540
Subject(s) - x ray photoelectron spectroscopy , overlayer , materials science , thin film , oxide , transmission electron microscopy , nanoparticle , analytical chemistry (journal) , chemical engineering , nanotechnology , chemistry , metallurgy , chromatography , engineering
We present results on the comparative studies of the surfaces of oxygen passivated FeCo nanoparticles (NPs) and thin films prepared by inert gas condensation and pulse laser deposition, respectively. Morphology and structure of the NPs and thin films are investigated by transmission electron microscopy (TEM) and X‐ray diffraction. Due to the larger surface area, thicker oxide over‐layer is observed for particles in comparison with thin films. X‐ray photoelectron spectroscopy (XPS) spectra strongly depended on the morphology and oxide over layer thicknesses for nanostructures. This leads to observation of clearly different background and is explained in term of different cationic distribution in the overlayer, thicknesses, and morphology (enhanced surface area) of the nanostructures. TEM analyses showed an oxide over‐layer on the NP of approximately 2.6 nm, which is consistent with the theoretical model based on electron attenuation lengths. However, in the case of thin films a much thinner oxide over‐layer of about 1.3 nm was observed. As expected, XPS spectra of oxygen passivated particles show oxide peaks with weak metal peaks compared to oxygen passivated thin films which show significantly high zero‐valent metal peaks.