Fe2O3-TiO2 systems grown by MOCVD: an XPS study

Abstract

The present work was devoted to the X-ray photoelectron spectroscopy (XPS) investigation of the principal core levels of a Fe2O3-TiO2 system. The sample was synthesized on a glass substrate at 430°C in N2/O2 atmospheres by low-pressure metal organic chemical vapor deposition (MOCVD) co-evaporating the precursors titanium(IV)isopropoxide [Ti(OiPr)4] and bis-(methylcyclopentadienyl)Fe(II) [Fe(MeCp)2] through independent sources. Beside the wide scan spectrum, detailed spectra for O 1s, Fe 2p and Ti 2p regions and related data are presented and discussed. XPS analysis revealed the presence of iron(III) and titanium(IV) oxides as the main phases, with a possible Fe2O3 segregation on the specimen surface

Nanostructured Fe2O3 Processing via Water‐Assisted ALD and Low‐Temperature CVD from a Versatile Iron Ketoiminate Precursor

“…The O1s spectra of a sample deposited at 125 °C ( Figure a) was characterized by the presence of two contributing bands at BE = 529.8 eV (green, 75.3% of total oxygen content after sputtering) and 531.3 eV (blue). According to literature, the former is best ascribed to lattice oxygen in Fe 2 O 3 , while the latter is related to the presence of hydroxyl groups, along with unsaturated oxygen species . The Fe2p (Figure b) signal shape and position [BE(Fe2p 3/2 ) = 710.9 eV, ΔFe2p = Fe2p 1/2 − Fe2p 3/2 = 13.6 eV] is in good agreement with previous reports on iron(III) oxides .…”

Tailoring iron(III) oxide nanomorphology by chemical vapor deposition: Growth and characterization

“…The Fe2p signal shape and position [BE(Fe2p 3/2 ) ¼ 711.3 eV, Fe2p 1/2 -Fe2p 3/2 energy separation ¼ 13.4 eV] was almost constant for all samples, and in good agreement with previous reports on iron(III) oxides ( Fig. 6c) [18,[48][49][50][51][52][53]. The Fe/O ratio, calculated basing only on lattice oxygen species (I) at lower binding energy, was found to be 0.72, in agreement with the stoichiometry expected for Fe 2 O 3 .…”

“…6b) was characterized by the presence of two contributing bands at BE ¼ 530.2 eV (I, black, 58.3% of total oxygen content) and 532.2 eV (species II, gray). Whereas the former could be ascribed to lattice oxygen in Fe 2 O 3 , the latter could be related to the presence of hydroxyl groups, along with coordinatively unsaturated oxygen species [18,[48][49][50]. The Fe2p signal shape and position [BE(Fe2p 3/2 ) ¼ 711.3 eV, Fe2p 1/2 -Fe2p 3/2 energy separation ¼ 13.4 eV] was almost constant for all samples, and in good agreement with previous reports on iron(III) oxides ( Fig.…”

Co3O4/TiO2heterostructures obtained by hybrid method

“…Therefore, it would be desirable to lower the effective band gap of TiO 2 in order to shift the absorption spectrum to the visible region. Extensive research has been carried out on the modification of TiO 2 band‐gap edge by different approaches, such as doping with different metals or non‐metal ions , surface treatments with organic compounds or inorganic metal complexes , or by coupling with narrow band‐gap semiconductors .…”