Investigation of Fe/Al interface as a function of annealing temperature using XPS

Brajpuriya, R.; Shripathi, T.

doi:10.1016/j.apsusc.2009.01.070

Cited by 60 publications

(28 citation statements)

References 32 publications

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“…The structural characteristics of these alloys have been related to the magnetic properties and different phases like ferromagnetic (FM), paramagnetic (PM), spin-glass (SG) and re-entrant spin glass are reported [6,7,8,9,10]. X-ray photoemission (XPS) valence band of FeAl multilayer sample showed appreciable changes in the Fe 3d and the Al 3s density of states as a function of annealing which are attributed to the strong sp − d hybridization at the Fermi level (E F ) [11]. Oku et al [12] reported a magnetic moment of 1.7 µ B in the PM phase from the analysis of Fe 3s XPS core level spectra.…”

Section: Introductionmentioning

confidence: 99%

Electronic structure of FeAl alloy studied by resonant photoemission spectroscopy and Ab initio calculations

Mondal

Banik

Kamal

et al. 2016

Journal of Alloys and Compounds

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Abstract. Resonant photoemission spectroscopy has been used to investigate the character of Fe 3d states in FeAl alloy. Fe 3d states have two different character, first is of itinerant nature located very close to the Fermi level, and second, is of less itinerant (relatively localized character), located beyond ∼2 eV below the Fermi level. These distinct states are clearly distinguishable in the resonant photoemission data. Comparison between the results obtained from experiments and first principle based electronic structure calculation show that the origin of the itinerant character of the Fe 3d states is due to the ordered B2 structure, whereas the relatively less itinerant (localized) Fe 3d states are from the disorders present in the sample. The exchange splitting of the Fe 3s core level peak confirms the presence of local moment in this system. It is found that the itinerant electrons arise due to the hybridization between Fe 3d and Al 3s − 3p states. Presence of hybridization is observed as a shift in the Al 2p core-level spectra as well as in the X-ray near edge absorption spectra towards lower binding energy. Our photoemission results are thus explained by the co-existence of ordered and disordered phases in the system.

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Section: Introductionmentioning

confidence: 99%

Electronic structure of FeAl alloy studied by resonant photoemission spectroscopy and Ab initio calculations

Mondal

Banik

Kamal

et al. 2016

Journal of Alloys and Compounds

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“…Over the reduced catalysts of MNC0.5F0.3 and MNC0.0F0.8 in Figure 6a,b and Table 3, there are strong peaks of Fe 0 with a molar ratio of Fe 0 /(Fe 0 + Fe 2+ + Fe 3+ ) near 70.9% and 77.6%, respectively, which is consistent with the strong peaks of Fe or Fe-rich Ni-Fe alloy in XRD (Figure 4a). For the Fe species in reduced catalysts, as shown in Figure 6, the spectra of Fe 2p 3/2 can be deconvoluted into six peaks; among these peaks, the peak near 706.8 eV can be assigned to Fe 0 , while other peaks near 709.8 eV, 710.8 eV, 711.6 eV, 712.6 eV, and 713.7 eV can be assigned to oxides of Fe 2+ /Fe 3+ [22][23][24]. Over the reduced catalysts of MNC 0.5 F 0.3 and MNC 0.0 F 0.8 in Figure 6a,b and Table 3, there are strong peaks of Fe 0 with a molar ratio of Fe 0 /(Fe 0 + Fe 2+ + Fe 3+ ) near 70.9% and 77.6%, respectively, which is consistent with the strong peaks of Fe or Fe-rich Ni-Fe alloy in XRD (Figure 4a).…”

Section: Reduced Catalystsmentioning

confidence: 99%

Dolomite-Derived Ni-Based Catalysts with Fe Modification for Hydrogen Production via Auto-Thermal Reforming of Acetic Acid

et al. 2016

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Bio-oil can be obtained via fast pyrolysis of biomass, and typically contains acetic acid (~30 mass %). The acetic acid has often been tested as a model compound for hydrogen production via reforming bio-oil, in which catalysts are a key factor for stable hydrogen production. However, deactivation of catalysts by coking and oxidation hinders the application of the reforming process. Dolomite-derived Ni-based catalysts with Fe additive, MgNi 0.2 Ca 0.8´x Fe x O 2˘δ (x = 0-0.8), were successfully synthesized by the hydrothermal synthesis method, and then tested in auto-thermal reforming (ATR) of acetic acid (AC). The MgNi 0.2 Ca 0.5 Fe 0.3 O 2˘δ catalyst performed a stable reactivity in ATR: the conversion of AC reached 100%, and the H 2 yield remained stable around 2.6 mol-H 2 /mol-AC. The catalysts were characterized by X-ray diffraction (XRD), N 2 physisorption, X-ray photoelectron spectra (XPS), H 2 -temperature-programmed reduction (TPR), inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and Thermogravimetry (TG); the results show that a periclase-like solid solution of Mg(Ni,Fe)O and lime were formed via the precursors of dolomite and hydrotalcite, and then transformed into Fe-rich Ni-Fe alloy with basic support of MgO-CaO after reduction. The stable Ni 0 spices with basic support can explain the stability and resistance to coking during ATR of AC.

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“…1a). The interfaces between the layers are not very sharp, which is an effect of limited depth resolution of AES (*3 nm) at these analytical conditions and thin metallic layers (several tens of nanometers), a broad interface (*2 nm) is formed between Al and Fe layers due to the diffusion of highly mobile Al atoms into the relatively immobilize Fe lattice, even at room temperature [7,24]. Also, interdiffusion between thin film components and Si from the substrate occurred at interfaces, where Al and Si were dominant diffusion species in observed system.…”

Section: Resultsmentioning

confidence: 98%

“…Fabrication of highly arranged nanostructures in Al/Fe multilayer form has been the subject of several researches motivated by the interest in their soft magnetic properties, including low coercivity and high saturation magnetization, as well as by their potential application as high-temperature structural and corrosionresistant materials [4][5][6][7]. Aside from these properties, one focus of the research with Al/Fe multilayer structures has been the formation of intermetallic compounds and metallic oxides during post-deposition treatment [8].…”

Section: Introductionmentioning

confidence: 99%

Synthesis of ultra-thin oxide layer in laser-treated 3× (Al/Fe)/Si multilayer structure

et al. 2014

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The conditions of ultra-thin oxide films synthesized as the Al/Fe multilayer structures after the surface treatment with femtosecond laser radiation were studied. Thin films composed of three (Al/Fe) bilayers were deposited by DC ion sputtering on (100) Si wafers to the total thickness of 410 nm. Laser irradiations were performed by 40-fs pulses of a Ti:Sapphire laser operating at 800 nm, at fluences slightly higher than the ablation threshold. The samples were characterized by Auger electron spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. Progressed intermixing of components was achieved for the irradiation with fluence of 0.43 J cm -2 , when intermetallic phase was formed and all components were almost uniformly distributed through the entire multilayer structure. Exception is the subsurface region, to the thickness of 20 nm, where the distribution of constructive components and their oxide is changing with the distance from the surface, and this distribution depends on the applied laser fluences. An ultrathin oxide layer was formed at the surface, with the specific combination of the oxide phases, Al 2 O 3 and Fe 2 O 3 , depending on the applied fluences. Laser-induced modification was accompanied with the ablation of the material and the creation of parallel periodic structures. These effects of laser-induced morphological features are increased with increasing laser fluences, caused by the pronounced mobility of the materials. The special morphology of the laser-assisted synthesis of mixture of Al 2 O 3 and Fe 2 O 3 in the form of an ultra-thin oxide layer can improve their characteristics for functional applications, as catalysts and sensors.

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Investigation of Fe/Al interface as a function of annealing temperature using XPS

Cited by 60 publications

References 32 publications

Electronic structure of FeAl alloy studied by resonant photoemission spectroscopy and Ab initio calculations

Electronic structure of FeAl alloy studied by resonant photoemission spectroscopy and Ab initio calculations

Dolomite-Derived Ni-Based Catalysts with Fe Modification for Hydrogen Production via Auto-Thermal Reforming of Acetic Acid

Synthesis of ultra-thin oxide layer in laser-treated 3× (Al/Fe)/Si multilayer structure

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