scholarly journals Deposit of AlN thin films by nitrogen reactive pulsed laser ablation using an Al target

2019 ◽  
Vol 65 (4 Jul-Aug) ◽  
pp. 345 ◽  
Author(s):  
F. Chale-Lara ◽  
M. Zapata-Torres ◽  
F. Caballero-Briones ◽  
W. De la Cruz ◽  
N. Cruz Gonzalez ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Photoelectron Spectroscopy ◽  
Hexagonal Phase ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Nitrogen Pressure ◽  
Binding Energies ◽  
Xps Spectra ◽  
X Ray

We report the synthesis of AlN hexagonal thin films by pulsed laser ablation, using Al target in nitrogen ambient over natively-oxidized Si (111) at 600°C. Composition and chemical state were determined by X-ray photoelectron spectroscopy (XPS); while structural properties were investigated using X-ray diffraction (XRD). High-resolution XPS spectra present a gradual shift to higher binding energies on the Al2ppeak when nitrogen pressure is incremented, indicating the formation of the AlN compound. At 30 mTorr nitrogen pressure, theAl2p peak corresponds to AlN, located at 73.1 eV, and the XRD pattern shows a hexagonal phase of AlN. The successful formation of the AlN compound is corroborated by UV-Vis reflectivity measurements.

Characterization of BaTiO3 Thin Films Deposited by Pulsed-Laser Ablation

1990 ◽  
Vol 201 ◽  
Author(s):  
Christopher Scarfone ◽  
M. Grant Norton ◽  
C. Barry Carter ◽  
Jian Li ◽  
James W. Mayer
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Pulsed Laser ◽  
Film Surface ◽  
Pulsed Laser Ablation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ion Channeling ◽  
Very High

AbstractThin films of barium titanate (BaTiOs) have been deposited by pulsed-laser ablation onto (001)-oriented MgO substrates. The films were epitactic as evidenced by both x-ray diffraction and ion-channeling techniques. The film surface appeared smooth and contained a low density of particulates. This latter feature is believed to be due to the formation of target pellets having a very high density.

scholarly journals PL Tunable GaN Nanoparticles Synthesis through Femtosecond Pulsed Laser Ablation in Different Environments

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 439 ◽  
Author(s):  
Juan Hao ◽  
Sijia Xu ◽  
Bingrong Gao ◽  
Lingyun Pan
Keyword(s):  
Laser Ablation ◽  
Photoelectron Spectroscopy ◽  
Pulse Laser Ablation ◽  
Optoelectronic Devices ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Alternative Methods ◽  
X Ray ◽  
Pl Spectra ◽  
Bulk Gan

The tunable photoluminescence (PL) property is very important for gallium nitride (GaN) nanoparticles in the application of ultraviolet and blue optoelectronic devices, while conventional methods are not so satisfactory that alternative methods for preparing GaN nanoparticles should be studied. In this paper, ultra-small and well dispersed GaN nanoparticles are fabricated through femtosecond pulse laser ablation in air, water and ethanol. For the PL spectra of GaN nanoparticles, there are no shifts in air, red shifts in water and blue shifts in ethanol compared with the intrinsic PL spectra of bulk GaN. The X-ray photoelectron spectroscopy (XPS) results demonstrate that the various PL spectra can be due to the different components inside the GaN nanoparticles, which not only have effect on the PL emissions, but also greatly influence the intensity of PL. This study validates that the ablation environment has a great adjustable effect on the properties of GaN nanoparticles.

scholarly journals Enhancement of Electrical Property of Carbon Nanotube by Silicon Incorporation

2020 ◽  
Vol 10 (1) ◽  
pp. 62-65
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Binding Energies ◽  
Xps Spectra ◽  
X Ray ◽  
Conductivity Increase ◽  
Vapor Deposition Technique ◽  
Si Content

Silicon incorporated carbon nano tube has been synthesized by radio frequency plasma enhanced chemical vapor deposition technique with acetylene gas. Tetraethyl orthosilicate solution was used for the synthesis of silicon incorporation in the CNT thin films. Energy dispersive X-ray analysis shows that the Si atomic percentage in the CNT thin films varied from 0 % to 3.82 %. The different chemical binding energies of carbon and silicon were analyzed from X-ray photoelectron spectroscopy spectra. In the XPS spectra, the peaks at ~531 eV, ~ 285 eV, ~151 eV and ~100 eV are the contributions from O 1s, C 1s, Si 2s and Si 2p respectively. Nanostructure morphologies of the Si-CNT thin films have been analyzed by field emission scanning electron microscopy. The length of the silicon incorporated carbon nano tubes ~100 nm and corresponding diameter ~20 nm. The increase of atomic percentage of Si in the CNT thin films, room temperature electrical conductivity increases. The electrical conductivity increase from 3.87x103 to 4.49x104 S cm-1 as the silicon atomic percentage in the CNT thin films increases from 0 to 3.82 % respectively. This study showed that the Si-CNTs thin films potentially useful in electrical application of varying its conductivity by changing the Si content independently from other parameters

scholarly journals Influence of Titania Synthesized by Pulsed Laser Ablation on the State of Platinum during Ammonia Oxidation

2020 ◽  
Vol 10 (14) ◽  
pp. 4699
Author(s):  
Andrey Stadnichenko ◽  
Dmitry Svintsitskiy ◽  
Lidiya Kibis ◽  
Elizaveta Fedorova ◽  
Olga Stonkus ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Photoelectron Spectroscopy ◽  
Ammonia Oxidation ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Active Species ◽  
Laser Ablation In Liquid ◽  
X Ray ◽  
Catalytically Active ◽  
Physicochemical Methods

A set of physicochemical methods, including X-ray photoelectron spectroscopy (XPS), X-ray diraction, electron microscopy and X-ray absorption spectroscopy, was applied to study Pt/TiO2 catalysts prepared by impregnation using a commercial TiO2-P25 support and a support produced by pulsed laser ablation in liquid (PLA). The Pt/TiO2-PLA catalysts showed increased thermal stability due to the localization of the highly dispersed platinum species at the intercrystalline boundaries of the support particles. In contrast, the Pt/TiO2-P25 catalysts were characterized by uniform distributionof the Pt species over the support. Analysis of Pt4f XP spectra shows that oxidized Pt2+ and Pt4+ species are formed in the Pt/TiO2-P25 catalysts, while the platinum oxidation state in the Pt/TiO2-PLA catalysts is lower due to stronger interaction of the active component with the support due to stronginteraction via Pt-O-Ti bonds. The Pt4f XP spectra of the samples after reaction show Pt2+ and metallic platinum, which is the catalytically active species. The study of the catalytic properties in ammonia oxidation showed that, unlike the catalysts prepared with a commercial support, the Pt/TiO2-PLA samples show higher stability during catalysis and significantly higher selectivity to N2 in a wide temperature range of 200–400 C.

Thin Films of SrFeO2.5+x - Effect of Preferred Orientation on Oxygen Uptake

1994 ◽  
Vol 343 ◽  
Author(s):  
Brian W. Sanders ◽  
Jianhua Yao ◽  
Michael L. Post
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Oxygen Uptake ◽  
Growth Temperature ◽  
Deposition Temperature ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oriented Films

ABSTRACTPulsed laser ablation has been used to deposit thin films of SrFeO25+x (x = 0 to ≈0.5). Previous work has shown that the orientation of the films, determined by powder x-ray diffraction depended strongly upon the deposition temperature. Films grown below 770 K showed little or no orientation. A growth temperature of 900 K resulted in films oriented (200). Growth temperatures of > 1000 K produced films oriented predominantly (110). At 673 K in an oxygen atmosphere, oriented films readily converted from the oxygen deficient brownmillerite form (x=0) to the oxygen rich cubic (or distorted cubic) perovskite form (x≈0.3). Films which exhibited no initial orientation did not react with oxygen under these conditions. Cycling non-oriented films between 230 and 800 ppm of oxygen in 101.3 kPa of nitrogen at 673 K resulted in weak (110) orientation. Once oriented, the films reacted readily with oxygen and exhibited measurable resistance changes. The conversion from oxygen deficient to oxygen rich form was monitored by x-ray diffraction and the DC resistance of the films.

scholarly journals Enhancing electrical properties of carbon nanotubes thin films by silicon incorporation

2021 ◽  
Vol 1206 (1) ◽  
pp. 012028
Author(s):  
Sk Faruque Ahmed ◽  
Mohibul Khan ◽  
Nillohit Mukherjee
Keyword(s):  
Thin Films ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Chemical Vapor ◽  
Binding Energies ◽  
Xps Spectra ◽  
X Ray ◽  
Vapor Deposition Technique

Abstract Silicon incorporated carbon nanotube (Si-CNTs) thin films was prepared by radio frequency plasma enhanced chemical vapor deposition technique. Tetraethyl orthosilicate solution was used for incorporation of silicon in CNTs thin films. Energy dispersive X-ray analysis shows that the silicon atomic percentage was varied from 0 % to 6.1 %. The chemical binding energies of carbon and silicon were analyzed from X-ray photoelectron spectroscopy data. The various peaks at ~531 eV, ~ 285 eV, ~155 eV and ~104 eV was observed in the XPS spectra due to the oxygen, carbon and silicon respectively. Surface morphologies of Si-CNTs thin films have been analyzed by field emission scanning electron microscopy, which revels that the length of the silicon incorporated carbon nanotubes ~500 nm and corresponding diameter ~80 nm. The room temperature electrical conductivity was increased whereas the activation energy was decreased with the increase of atomic percentage of silicon in Si-CNTs thin films. The room temperature electrical conductivity was increased from 4.3 × 103 to 7.1 × 104 S cm−1 as the silicon atomic percentage in Si-CNTs thin films increases from 0 to 6.1 % respectively.

Synthesis of thin films of polycrystalline ferroelectric BiNbO4 on Si by pulsed laser ablation

1998 ◽  
Vol 13 (5) ◽  
pp. 1113-1116 ◽  
Author(s):  
Soma Chattopadhyay ◽  
Pushan Ayyub ◽  
R. Pinto ◽  
M. S. Multani
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Polycrystalline Thin Films ◽  
Ambient Oxygen

The stibiotantalite (ABO4) family includes a number of ferroelectrics and antiferroelectrics with excellent potential for applications. We report the deposition of phase-pure, polycrystalline thin films of BiNbO4 on Si(100) substrates using pulsed laser ablation. The deposition conditions were optimized with respect to substrate temperature, laser parameters, and the ambient oxygen pressure. The films were characterized by x-ray diffraction, energy dispersive x-ray analysis, and Raman spectroscopy, while their microstructure was studied by atomic force microscopy and scanning electron microscopy. Dielectric hysteresis studies indicated that films with a thickness below ≈250 nm are ferroelectric, while thicker ones are antiferroelectric.

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