Electronic Study of Pt-Ga Intermetallic Compounds Using X-Ray Photoemission Spectroscopy

Nearly single-phase thin films of three different Pt–Ga intermetallic compounds have been grown on GaAs(001) by co-deposition of Pt and Ga. The resultant films have been annealed at various temperatures and then characterized using x-ray two-theta diffractometry (XRD), Auger electron spectroscopy (AES), and x-ray photoemission spectroscopy (XPS). The XRD results showed that PtGa2 and PtGa thin films are chemically stable on GaAs under one atmosphere of N2 up to 800 °C and 600 °C, respectively, but thin films of Pt2Ga react with GaAs at temperatures as low as 200 °C to form phases with higher Ga concentration PtAs2. The XRD patterns also revealed that the crystallite orientation and texture of the films were dependent on annealing temperature. Segregation of Ga to the surfaces of the films upon annealing was also observed by both AES and XPS. The results demonstrated that the as-deposited films of PtGa2 and PtGa were kinetically stabilized with respect to possible chemical reactions with the GaAs substrates that evolve gaseous As species during open system annealing.

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Synthesis and characterization of TiN / Ti / AISI 410 coatings

Journal of Sciences and Engineering ◽

10.32829/sej.v2i1.54 ◽

2018 ◽

Vol 2 (1) ◽

pp. 7

Author(s):

S Chirino ◽

Jaime Diaz ◽

N Monteblanco ◽

E Valderrama

Keyword(s):

Synthesis And Characterization ◽

Photoemission Spectroscopy ◽

X Ray Diffraction ◽

X Ray ◽

Columnar Grains ◽

Tin Thin Films ◽

Steel Aisi ◽

Interacting Surfaces ◽

Stainless Steel Aisi

The synthesis and characterization of Ti and TiN thin films of different thicknesses was carried out on a martensitic stainless steel AISI 410 substrate used for tool manufacturing. The mechanical parameters between the interacting surfaces such as thickness, adhesion and hardness were measured. By means of the scanning electron microscope (SEM) the superficial morphology of the Ti/TiN interface was observed, finding that the growth was of columnar grains and by means of EDAX the existence of titanium was verified. Using X-ray diffraction (XRD) it was possible to observe the presence of residual stresses (~ -3.1 GPa) due to the different crystalline phases in the coating. Under X-ray photoemission spectroscopy (XPS) it was possible to observe the molecular chemical composition of the coating surface, being Ti-N, Ti-N-O and Ti-O the predominant ones.

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Electronic Structure of n-Cycloparaphenylenes Directly Observed by Photoemission Spectroscopy

Physical Chemistry Chemical Physics ◽

10.1039/d1cp00625h ◽

2021 ◽

Author(s):

Kaname Kanai ◽

Takuya Inoue ◽

Takaya Furuichi ◽

Kaito Shinoda ◽

Takashi Iwahashi ◽

...

Keyword(s):

Electronic Structure ◽

Electronic Structures ◽

Photoemission Spectroscopy ◽

Cyclic Structure ◽

Visible Absorption ◽

X Ray ◽

Inverse Photoemission

A series of n-cycloparaphenylenes ([n]CPP) were studied by ultraviolet photoemission, inverse photoemission, ultraviolet-visible absorption, and X-ray photoemission spectroscopy to detect their unique electronic structures. [n]CPP has a cyclic structure in...

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The Degree of Oxidation of Graphene Oxide

Nanomaterials ◽

10.3390/nano11030560 ◽

2021 ◽

Vol 11 (3) ◽

pp. 560

Author(s):

Alexandra Carvalho ◽

Mariana C. F. Costa ◽

Valeria S. Marangoni ◽

Pei Rou Ng ◽

Thi Le Hang Nguyen ◽

...

Keyword(s):

Graphene Oxide ◽

Ab Initio ◽

State Of The Art ◽

High Accuracy ◽

Precise Determination ◽

Photoemission Spectroscopy ◽

Pristine Graphene ◽

X Ray ◽

Degree Of Oxidation

We show that the degree of oxidation of graphene oxide (GO) can be obtained by using a combination of state-of-the-art ab initio computational modeling and X-ray photoemission spectroscopy (XPS). We show that the shift of the XPS C1s peak relative to pristine graphene, ΔEC1s, can be described with high accuracy by ΔEC1s=A(cO−cl)2+E0, where c0 is the oxygen concentration, A=52.3 eV, cl=0.122, and E0=1.22 eV. Our results demonstrate a precise determination of the oxygen content of GO samples.

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Characterization of Charge States in Conducting Organic Nanoparticles by X-ray Photoemission Spectroscopy

Materials ◽

10.3390/ma14082058 ◽

2021 ◽

Vol 14 (8) ◽

pp. 2058

Author(s):

Jordi Fraxedas ◽

Antje Vollmer ◽

Norbert Koch ◽

Dominique de Caro ◽

Kane Jacob ◽

...

Keyword(s):

Partial Oxidation ◽

Chemical Shifts ◽

Large Family ◽

Photoemission Spectroscopy ◽

Intrinsic Structure ◽

X Ray ◽

Level Lines ◽

Donor And Acceptor ◽

Electronic Configurations

The metallic and semiconducting character of a large family of organic materials based on the electron donor molecule tetrathiafulvalene (TTF) is rooted in the partial oxidation (charge transfer or mixed valency) of TTF derivatives leading to partially filled molecular orbital-based electronic bands. The intrinsic structure of such complexes, with segregated donor and acceptor molecular chains or planes, leads to anisotropic electronic properties (quasi one-dimensional or two-dimensional) and morphology (needle-like or platelet-like crystals). Recently, such materials have been synthesized as nanoparticles by intentionally frustrating the intrinsic anisotropic growth. X-ray photoemission spectroscopy (XPS) has emerged as a valuable technique to characterize the transfer of charge due to its ability to discriminate the different chemical environments or electronic configurations manifested by chemical shifts of core level lines in high-resolution spectra. Since the photoemission process is inherently fast (well below the femtosecond time scale), dynamic processes can be efficiently explored. We determine here the fingerprint of partial oxidation on the photoemission lines of nanoparticles of selected TTF-based conductors.

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Hard X-ray Photoemission Spectroscopy for Probing Bulk Electronic Structures of Solids

Hyomen Kagaku ◽

10.1380/jsssj.28.698 ◽

2007 ◽

Vol 28 (12) ◽

pp. 698-703 ◽

Cited By ~ 1

Author(s):

Koji HORIBA

Keyword(s):

Electronic Structures ◽

Photoemission Spectroscopy ◽

X Ray

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Study of Structural, Magnetic, and Mossbauer Properties of Dy2Fe16Ga1−xNbx (0.0 ≤ x ≤ 1.0) Prepared via Arc Melting Process

Magnetochemistry ◽

10.3390/magnetochemistry7030042 ◽

2021 ◽

Vol 7 (3) ◽

pp. 42

Author(s):

Jiba N. Dahal ◽

Kalangala Sikkanther Syed Ali ◽

Sanjay R. Mishra

Keyword(s):

Isomer Shift ◽

Cell Volume ◽

Intermetallic Compounds ◽

Unit Cell Volume ◽

Rietveld Analysis ◽

Unit Cell ◽

X Ray Diffraction ◽

X Ray ◽

Arc Melting ◽

Nb Content

Intermetallic compounds of Dy2Fe16Ga1−xNbx (x = 0.0 to 1.00) were synthesized by arc melting. Samples were investigated for structural, magnetic, and hyperfine properties using X-ray diffraction, vibration sample magnetometer, and Mossbauer spectrometer, respectively. The Rietveld analysis of room temperature X-ray diffraction data shows that all the samples were crystallized in Th2Fe17 structure. The unit cell volume of alloys increased linearly with an increase in Nb content. The maximum Curie temperature Tc ~523 K for x = 0.6 sample is higher than Tc = 153 K of Dy2Fe17. The saturation magnetization decreased linearly with increasing Nb content from 61.57 emu/g for x = 0.0 to 42.46 emu/g for x = 1.0. The Mössbauer spectra and Rietveld analysis showed a small amount of DyFe3 and NbFe2 secondary phases at x = 1.0. The hyperfine field of Dy2Fe16Ga1−xNbx decreased while the isomer shift values increased with the Nb content. The observed increase in isomer shift may have resulted from the decrease in s electron density due to the unit cell volume expansion. The substantial increase in Tc of thus prepared intermetallic compounds is expected to have implications in magnets used for high-temperature applications.

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