Investigation of the Effect of Uv-Assisted Oxidation and Nitridation of Hafnium Metal Films

2003 ◽  
Vol 780 ◽  
Author(s):  
C. Essary ◽  
V. Craciun ◽  
J. M. Howard ◽  
R. K. Singh

AbstractHf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.

2013 ◽  
Vol 28 (2) ◽  
pp. 68-71 ◽  
Author(s):  
Thomas N. Blanton ◽  
Debasis Majumdar

In an effort to study an alternative approach to make graphene from graphene oxide (GO), exposure of GO to high-energy X-ray radiation has been performed. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) have been used to characterize GO before and after irradiation. Results indicate that GO exposed to high-energy radiation is converted to an amorphous carbon phase that is conductive.


2016 ◽  
Vol 689 ◽  
pp. 55-59
Author(s):  
Serge Zhuiykov

Electrical properties and morphology of orthorhombic β–WO3 nano-flakes with thickness of ~7-9 nm were investigated at the nanoscale using energy dispersive X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and current sensing force spectroscopy atomic force microscopy (CSFS-AFM, or PeakForce TUNATM). CSFS-AFM analysis established good correlation between the topography of the developed nanostructures and various features of WO3 nano-flakes synthesized via a two-step sol-gel-exfoliation method. It was determined that β–WO3 nano-flakes annealed at 550°C possess distinguished and exceptional thickness-dependent properties in comparison with the bulk, micro- and nano-structured WO3 synthesized at alternative temperatures.


2012 ◽  
Vol 545 ◽  
pp. 290-293
Author(s):  
Maryam Amirhoseiny ◽  
Hassan Zainuriah ◽  
Ng Shashiong ◽  
Mohd Anas Ahmad

We have studied the effects of deposition conditions on the crystal structure of InN films deposited on Si substrate. InN thin films have been deposited on Si(100) substrates by reactive radio frequency (RF) magnetron sputtering method with pure In target at room temperature. The nitrogen gas pressure, applied RF power and the distance between target and substrate were 2×10-2 Torr, 60 W and 8 cm, respectively. The effects of the Ar–N2 sputtering gas mixture on the structural properties of the films were investigated by using scanning electron microscope, energy-dispersive X-ray spectroscopy, atomic force microscopy and X-ray diffraction techniques.


2013 ◽  
Vol 20 (01) ◽  
pp. 1350006 ◽  
Author(s):  
PARTHASARATHI BERA ◽  
H. SEENIVASAN ◽  
K. S. RAJAM

Co–W alloy coatings were deposited with direct current (DC) and pulse current (PC) electrodeposition methods using gluconate bath at pH5 and characterized by X-ray diffraction, field emission scanning electron microscopy, atomic force microscopy, differential scanning calorimetry (DSC) and X-ray photoelectron spectroscopy (XPS). DSC studies hint at the possibility of formation of metallic glasses. Detailed XPS studies of these alloy coatings have been carried out to compare elemental states and composition of Co and W in DC and PC electrodeposited alloys. DC-plated alloy has significant amount of Co and W metal along with their respective oxidized species. In contrast, mainly oxidized metals are present in the following layers of as-deposited coatings prepared with PC plating. Concentration of Co metal is observed to increase during sputtering, whereas there is no change in W6+ concentration. Microhardness measurement of all the Co–W coatings shows higher hardness compared to Co metal and 1:1 and 1:4 PC electrodeposited coatings show little higher hardness compared to 1:2 PC electrodeposited coating.


2021 ◽  
Author(s):  
Reshma P R ◽  
Anees Pazhedath ◽  
Ganesan Karuppiah ◽  
Arun Prasad ◽  
Sandip Dhara

Abstract Recently emerged transition metal oxide (TMO) based 2D nanostructures are gaining a foothold in advanced applications. Unlike, 2D transition metal dichalchogenides, it is strenuous to obtain high quality thin TMOs due to exotic surface reconstruction during synthesis. Herein, we report the synthesis of bilayer thin 2D-V2O5 nanosheets using chemical exfoliation. Synchrotron X-ray diffraction, X-ray photoelectron spectroscopy and atomic force microscopy substantiate the successful formation of bilayer thin 2D-V2O5. Ultraviolet-visible absorption spectra exhibit a thickness dependent blue shift in the optical band gap, signifying the emergence of electronic decoupling. Raman spectroscopy fingerprinting shows a thickness dependent vibrational decoupling of phonon modes. Further, it has been verified by computing the lattice vibrational modes using density functional perturbation theory. In this study, the manifestation of the electronic and vibrational decoupling is used as a novel probe to confirm the successful exfoliation of bilayer 2D-V2O5 from its bulk counterpart.


2011 ◽  
Vol 467-469 ◽  
pp. 312-315
Author(s):  
Gang Li ◽  
Wen Ming Cheng

Ultra-thin (20 nm) nickel catalyst films were deposited by sputtering on SiO2/Si substrates. At the pretreatments, ammonia (NH3) was conducted for different time in a thermal chemical vapor deposition (CVD) system. Pretreated samples were characterized using atomic force microscopy (AFM). After the pretreatment, acetylene was introduced into the chamber for 10 min, samples were characterized using scanning electron micrograph (SEM) and X-ray diffraction (XRD). It was concluded that NH3 pretreatment was very crucial to control the surface morphology of catalytic metals and thus to achieve the vertical alignment of carbon nanotubes (CNTs). With higher density of the Ni particles, better alignment of the CNTs can be obtained due to steric hindrance effect between neighboring CNTs.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Angela De Bonis ◽  
Agostino Galasso ◽  
Antonio Santagata ◽  
Roberto Teghil

A MgB2target has been ablated by Nd:glass laser with a pulse duration of 250 fs. The plasma produced by the laser-target interaction, showing two temporal separated emissions, has been characterized by time and space resolved optical emission spectroscopy and ICCD fast imaging. The films, deposited on silicon substrates and formed by the coalescence of particles with nanometric size, have been analyzed by scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, micro-Raman spectroscopy, and X-ray diffraction. The first steps of the films growth have been studied by Transmission Electron Microscopy. The films deposition has been studied by varying the substrate temperature from 25 to 500°C and the best results have been obtained at room temperature.


Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 644
Author(s):  
Minh Tran ◽  
Sougata Roy ◽  
Steven Kmiec ◽  
Alison Whale ◽  
Steve Martin ◽  
...  

Gold (Au) and copper (Cu)-based nanostructures are of great interest due to their applicability in various areas including catalysis, sensing and optoelectronics. Nanostructures synthesized by the galvanic displacement method often lead to non-uniform density and poor size distribution. Here, density and size-controlled synthesis of Au and Cu-based nanostructures was made possible by galvanic displacement with limited exposure to hydrofluoric (HF) acid and the use of surfactants like L-cysteine (L-Cys) and cetyltrimethylammonium bromide (CTAB). An approach involving cyclic exposure to HF acid regulated the nanostructure density. Further, the use of surfactants generated monodisperse nanoparticles in the initial stages of the deposition with increased density. The characterization of Au and Cu-based nanostructures was performed by scanning electron microscopy, atomic force microscopy, UV-Visible spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy and X-ray diffraction. The surface enhanced Raman spectroscopic measurements demonstrated an increase in the Raman intensity by two to three orders of magnitude for analyte molecules like Rhodamine 6G dye and paraoxon.


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