XPS Study in BiFeO3 Surface Modified by Argon Etching

Abstract

This paper reports an XPS surface study of pure phase BiFeO3 thin film produced and later etched by pure argon ions. Analysis of high-resolution spectra from Fe 2p, Bi 4f and 5d, O 1s, and the valence band, exhibited mainly Fe3+ and Bi3+ components, but also reveal Fe2+. High-energy argon etching induces the growth of Fe(0) and Bi(0) and an increment of Fe2+, as expected. The BiFeO3 semiconductor character is preserved despite the oxygen loss, an interesting aspect for the study of the photovoltaic effect through oxygen vacancies in some ceramic films. The metal-oxygen bonds in O 1s spectra are related only to one binding energy contrary to the split from bismuth and iron reported in other works. All these data evidence that the low-pressure argon atmosphere is proved to be efficient to produce pure phase BiFeO3, even after argon etching.

Enhanced Cyclic Stability of Cobalt Doped Bi25FeO40/BiFeO3 as an Electrode Material for a Super Long Life Symmetric Supercapacitor Device

“…This may be due to the replacement of Fe ions by cobalt ions with the change in electron density. , The high intense peak of Fe 3+ confirmed its higher contribution compared to Fe 2+ . The formation of Fe 2+ ion gradually decreases when increasing the concentration of cobalt ion in BFCO3, which causes a slight distortion on the lattice structure and a possible double exchange interaction between 2+ and 3+ ions through oxygen (Fe 3+ -O-Fe 2+ ). − It confirms the replacement of Fe 3+ and Fe 2+ by Co 3+ and Co 2+ ions. These results correlate with the XRD analysis.…”

Role of Excess Bi on the Properties and Performance of BiFeO3 Thin-Film Photocathodes

“…The spectra are fitted with three contributions. The first feature (Peak 1; BFO-s: 529.5 eV; BFO-e: 529.6 eV) corresponds to lattice oxygen from BFO . The second feature (Peak 2; BFO-s: 531.0 eV; BFO-e: 531.1 eV) is attributed by some reports to oxygen adjacent to an oxygen vacancy (also referred to by some literature as dangling oxygen bonds), while others attribute this feature to hydroxyl species adsorbed on the surface. , Sometimes this feature is also erroneously attributed to oxygen vacancies directly. , Idriss emphasized that this feature corresponds to hydroxyl species adsorbed to the surface of metal oxides and discarded the role of oxygen vacancies as these would be readily oxidized when exposed to air .…”

Boosting the charge for the selective photoelectrochemical oxidation of hydroquinone in hazardous environments using a fine-tuned heterojunction catalyst

“…58 The effect of Ar-etching on the XPS spectrum of BiFeO 3 was studied and the Bi chemical shis were reported as: 158.6 eV and 164.4 eV for Bi 4f (7/2) and Bi 4f (5/2) transitions; while for Fe, eight peaks appeared at 732.7 eV, 728.4 eV, 724.8 eV, 723.2 eV, 719.0 eV, 714.1 eV, 711.3 eV and 710.1 eV assigned to Fe 3+ 2p (1/2) satellite, Fe 2+ 2p (1/2) satellite, Fe 3+ 2p (1/2) , Fe 2+ 2p (1/2) , Fe 3+ 2p (3/2) satellite, Fe 2+ 2p (3/2) satellite, Fe 3+ 2p (3/2) , and Fe 2+ 2p (3/2) satellite, respectively. 59 The comparison of the sets of peaks obtained for Bi and Fe in the Bi 2 S 3 /BiFeO 3 heterojunction to that obtained for the individual components of Bi 2 S 3 and BiFeO 3 conrmed the formation of the strong junction. Slight shis in the binding energies were observed for Bi and Fe in the heterojunction compared to that in the individual components.…”