Mullite Diffusion Barriers for SiC-C/C Composites Produced by Pulsed Laser Deposition

1998 ◽  
Vol 555 ◽  
Author(s):  
H. Fritze ◽  
A. Schnittker ◽  
T. Witke ◽  
C. Rüscher ◽  
S. Weber ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Target Material ◽  
High Energy ◽  
Single Step ◽  
Laser Deposition ◽  
Reduced Pressure ◽  
Oxidation Rates ◽  
Energy Impact ◽  
Diffusion Parameters

AbstractPulsed Laser Deposition (PLD) allows the ablation of nonconductive and high melting point target materials and the preparation of films with complex composition. High energy impact leads to melting and evaporation of the target material in a single step. In case of mullite ablation, the flux of the metal components is stoichiometric. Under reduced pressure the oxygen content in the layers decreases. However, after a short oxidation treatment, the formation of mullite in the coating is completed, as confirmed by IR spectroscopy and XRD investigations. For a commercial Si-SiC precoated C/C material, the effectiveness of additional PLD mullite layers as outer oxidation protection is tested in the temperature range 773 K < T < 1873 K. Mullite coatings with a thickness of 2.5 pm improve the oxidation behaviour significantly. Because of SiO2 formation at the mullite-SiC interface, all samples exhibited a mass increase upon oxidation. For oxidation durations of three days, only amorphous SiO2 is formed at the mullite-SiC interface. The inward diffusion of oxygen across the outer mullite-containing layer controls the kinetics of the reaction, as was deduced from 18O diffusivity measurements in PLD mullite layers. At temperatures close to the eutectic temperature (1860 K), mullite can seal defects. The calculated oxidation rates resulting from the diffusion parameters in SiO2 and mullite are close to the thermogravimetric data.

Comparison of Vanadium Oxide Thin Films Prepared Using Femtosecond and Nanosecond Pulsed Laser Deposition

MRS Advances ◽  
2016 ◽  
Vol 1 (39) ◽  
pp. 2737-2742 ◽  
Author(s):  
Ying Deng ◽  
Anthony Pelton ◽  
R. A. Mayanovic
Keyword(s):  
Thin Films ◽  
Vanadium Oxide ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Target Material ◽  
Laser Pulses ◽  
High Energy ◽  
Laser Deposition ◽  
Oxide Thin Films ◽  
Vanadium Oxide Thin Films

ABSTRACTPulsed laser deposition (PLD) is a technique which utilizes a high energy pulsed laser ablation of targets to deposit thin films on substrates in a vacuum chamber. The high-intensity laser pulses create a plasma plume from the target material which is projected towards the substrate whereupon it condenses to deposit a thin film. Here we investigate the properties of vanadium oxide thin films prepared utilizing two variations of the pulsed laser deposition (PLD) technique: femtosecond PLD and nanosecond PLD. Femtosecond PLD (f-PLD) has a significantly higher peak intensity and shorter duration laser pulse compared to that of the excimer-based nanosecond PLD (n-PLD). Experiments have been conducted on the growth of thin films prepared from V2O5 targets on glass substrates using f-PLD and n-PLD. Characterization using SEM, XRD and Raman spectroscopy shows that the f-PLD films have significantly rougher texture prior to annealing and exhibit with an amorphous nano-crystalline character whereas the thin films grown using n-PLD are much smoother and highly predominantly amorphous. The surface morphology, structural, vibrational, and chemical- and electronic-state elemental properties of the vanadium oxide thin films, both prior to and after annealing to 450 °C, will be discussed.

Fabrication of Ni–Al thin films by the pulsed laser deposition technique

1992 ◽  
Vol 7 (10) ◽  
pp. 2639-2642 ◽  
Author(s):  
R.K. Singh ◽  
Deepika Bhattacharya ◽  
S. Sharan ◽  
P. Tiwari ◽  
J. Narayan
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Rutherford Backscattering Spectrometry ◽  
Pulsed Laser ◽  
High Energy ◽  
Laser Deposition ◽  
Nanosecond Laser ◽  
X Ray ◽  
Target Composition

We have fabricated Ni3Al and NiAl thin films on different substrates by the pulsed laser deposition (PLD) technique. A high energy nanosecond laser beam was directed onto Ni–Al (NiAl, Ni3Al) targets, and the evaporated material was deposited onto substrates placed parallel to the target. The substrate temperature was varied between 300 and 400 °C, and the substrate-target distance was maintained at approximately 5 cm. The films were analyzed using scanning electron microscopy, transmission electron microscopy, x-ray diffraction, and Rutherford backscattering spectrometry. At energy densities slightly above the evaporation threshold, a slight enrichment of Al was observed, while at higher energy densities the film stoichiometry was close (<5%) to the target composition. Barring a few particles, the surface of the films exhibited a smooth morphology. X-ray and TEM results corroborated the formation of Ni3Al and NiAl films from similar target compositions. These films were characterized by small randomly oriented grains with grain size varying between 200 and 400 Å.

scholarly journals High energy storage performance in lead-free BiFeO3-BaTiO3 ferroelectric thin film fabricated by pulsed laser deposition

AIP Advances ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 085005 ◽  
Author(s):  
Yuqing Hu ◽  
Qingxiu Xie ◽  
Ruihong Liang ◽  
Xiangyong Zhao ◽  
Zhiyong Zhou ◽  
...  
Keyword(s):  
Thin Film ◽  
Energy Storage ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Ferroelectric Thin Film ◽  
High Energy ◽  
Laser Deposition ◽  
Lead Free ◽  
Storage Performance ◽  
High Energy Storage

Pulsed Laser Deposition of High-Quality Manganite Thin Films at Low Background Pressures with in-situ Reflection High Energy Electron Diffraction

2019 ◽  
Vol 3 (9) ◽  
pp. 55-63 ◽  
Author(s):  
Antonello Tebano ◽  
Carmela Aruta ◽  
Pier Gianni Medaglia ◽  
Giuseppe Balestrino ◽  
Norberto G. Boggio ◽  
...  
Keyword(s):  
Thin Films ◽  
Electron Diffraction ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
High Energy ◽  
Laser Deposition ◽  
High Energy Electron ◽  
High Quality ◽  
Low Background

Low Temperature Epitaxy of Si on Dihydride-Terminated Si (001): Energetic Versus Thermal Growth

1996 ◽  
Vol 441 ◽  
Author(s):  
M. E. Taylor ◽  
Harry A. Atwater ◽  
M. V. Ramana Murty
Keyword(s):  
Molecular Beam Epitaxy ◽  
Pulsed Laser Deposition ◽  
Molecular Beam ◽  
Pulsed Laser ◽  
High Energy ◽  
Interface Roughness ◽  
Laser Deposition ◽  
Cross Sectional ◽  
Comparison Of The Results ◽  
Si Films

AbstractPulsed laser deposition of Si on dihydride-terminated (l×1) Si (001) at low temperatures yields epitaxial layers, unlike molecular beam epitaxy. Si films were grown by ultrahigh vacuum pulsed laser deposition on the dihydride surface at substrate temperatures from 40 °C to 350 ° C. Epitaxial thickness and interface roughness were measured by high-resolution cross-sectional transmission electron microscopy and found to be comparable to known data for Si films grown by molecular beam epitaxy on monohydride-terminated (2×l) Si (001). Si films were grown at 200 °C by pulsed laser deposition on the dihydride surface at argon background pressures between 10− torr and 10−1 torr. Ion probe time of flight data was collected over the same pressure range. Comparison of the results suggests that loss of epitaxy is correlated with low incident energy. This, in conjunction with information on surface reconstruction obtained from reflection high-energy electron diffraction, suggests that the mechanism enabling epitaxy on the dihydride surface is Si subplantation, a mechanism only possible in growth with an energetic beam.

scholarly journals Pulsed Laser Deposition of Cs2AgBiBr6: from Mechanochemically Synthesized Powders to Dry, Single-Step Deposition

2021 ◽  
Vol 33 (18) ◽  
pp. 7417-7422 ◽  
Author(s):  
Nathan Rodkey ◽  
Stan Kaal ◽  
Paz Sebastia-Luna ◽  
Yorick A. Birkhölzer ◽  
Martin Ledinsky ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Single Step ◽  
Laser Deposition

Low Temperature Growth of Oriented Gallium Nitride using Pulsed Laser Deposition

1995 ◽  
Vol 395 ◽  
Author(s):  
Robert Leuchtner ◽  
W. Brock ◽  
Y. Li ◽  
L. Hristakos
Keyword(s):  
Pulsed Laser Deposition ◽  
Film Growth ◽  
Ambient Pressure ◽  
Pulsed Laser ◽  
Target Material ◽  
Deposition Process ◽  
Film Deposition ◽  
Laser Deposition ◽  
Metal Target ◽  
X Ray

ABSTRACTOriented GaN has been successfully grown at low substrate temperatures (∼480°C) on a- and r-planes of sapphire, using the pulsed laser deposition process. We have examined the effects of several deposition parameters on film growth, including substrate temperature (∼50–500°C), ambient pressure (1×10−3 – 10 torr of NH3), and target material (Ga or GaN). The film deposition rate was typically ∼3–4 μm/hr. Film characterization was performed using x-ray diffraction (XRD), optical microscopy, x-ray photoelectron spectrometry (XPS), and atomic force microscopy (AFM). In the case of the Ga metal target, a plasma (∼500V) between the target and substrate was necessary to promote formation of the GaN phase. The ammonia ambient enhanced the nitrogen content in the films compared to vacuum deposition. In general, the GaN target yielded better quality films (smaller rocking curve widths and smoother film morphology) compared to the Ga metal target. These results suggest that pulsed laser deposition is a promising approach to fabricating high quality films of this potentially important semiconducting material.

Growth of epitaxial β-FeSi2 thin films by pulsed laser deposition on silicon (111)

1994 ◽  
Vol 9 (11) ◽  
pp. 2733-2736 ◽  
Author(s):  
C.H. Olk ◽  
O. P. Karpenko ◽  
S. M. Yalisove ◽  
G. L. Doll ◽  
J.F. Mansfield
Keyword(s):  
Electron Diffraction ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
High Energy ◽  
Layer Growth ◽  
Laser Deposition ◽  
Electron Diffraction Data ◽  
Layer By Layer ◽  
Material System ◽  
Epitaxial Relationship

Epitaxial films of semiconducting iron disilicide (β-FeSi2) have been grown by pulsed laser deposition. We find that pulsed laser deposition creates conditions favorable to the formation of films with the smallest geometric misfit possessed by this material system. In situ reflection high energy electron diffraction results indicate a layer by layer growth of the silicide. Analysis of transmission electron diffraction data has determined that the films are single phase and that this growth method reproduces the epitaxial relationship: β-FeSi2 (001) ‖ Si(111).

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