Pulsed Laser Ablation as a Source of Energetic Reactants: Synthesis of Superconducting High to Thin Films

1990 ◽  
Vol 191 ◽  
Author(s):  
L. Lynds ◽  
B. R. Weinberger
Keyword(s):  
Laser Ablation ◽  
Pulsed Laser ◽  
Mass Range ◽  
Squid Magnetometry ◽  
Atomic Ions ◽  
Excimer Laser Ablation ◽  
Multiply Charged ◽  
Ion Energies ◽  
Cu Ions ◽  
Angular Energy

ABSTRACTPulsed KrF (248 nm) excimer laser ablation of targets can provide a source of atomic particles with energies in the range of 40 – 850 eV with beam-like characteristics. Optical intensities above about 109 W/cm2 lead mainly to single and multiply charged ground state positive atomic ions plus electrons with a pronounced angular energy dependence, the highest energies peaked in the direction normal to the target. A wide mass range of metallic and non-metallic targets were studied to determine the effects of atomic weights and other physical properties on the distribution of ion energies. Analysis of the energetics indicates that ablation mechanisms are non-equilibrium in nature. We have explored the use of very energetic (200–400 eV) Y, Ba and Cu ions to form very thin YBa2Cu3O7-x superconducting films grown on flat gold surfaces. SQUID magnetometry is used to study the temperature and field dependence of magnetization in these materials.

Preferential Crystallization of β-FeSi2 from Micro-droplets Generated by Laser Ablation.

2004 ◽  
Vol 848 ◽  
Author(s):  
Aiko Narazaki ◽  
Tadatake Sato ◽  
Yoshizo Kawaguchi ◽  
Hiroyuki Niino
Keyword(s):  
Laser Ablation ◽  
Room Temperature ◽  
Crystallization Behavior ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Excimer Laser Ablation ◽  
Pulsed Laser Annealing ◽  
Molten Droplets ◽  
Equilibrium Process ◽  
Krf Excimer Laser

ABSTRACTβ-FeSi2 was successfully fabricated at room temperature via the deposition of molten micro-droplets generated by the KrF excimer laser ablation. Only the molten droplets precipitated as the β-FeSi2 crystalline phase on a silicon substrate kept even at room temperature, whereas the rest of film was amorphous. The crystallization behavior of micro-droplets has been discussed in the light of non-equilibrium process due to rapid cooling on the substrate. After the deposition, pulsed laser annealing was also performed in order to improve the crystallinity of the β-FeSi2 microprecipitates-containing film.

Excimer Laser Ablation of Silicon at High Temperature

1998 ◽  
Vol 526 ◽  
Author(s):  
Y.F. Zhang ◽  
Y.H. Tang ◽  
C. S. Lee ◽  
N. Wang ◽  
I. Bello ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Laser Beam ◽  
Pulsed Laser ◽  
Target Surface ◽  
Si Nanowires ◽  
Beam Direction ◽  
Excimer Laser Ablation ◽  
Deep Channel ◽  
Porous Skeleton ◽  
Si Nanostructures

AbstractPulsed laser ablation of granulated Si target was carried out at 1200 °C in an Ar atmosphere. Multishot ablated target surface forms intensity dependent features, including porous, skeleton, and columnar structures. Very long columnar structures were observed when the angle of the target surface with respect to the direction of the laser beam was small. Evidence on preferable remove of smaller particles has been observed. Formation of the columnar structures started from the biggest particles at the surface and grew deeper, straight in the laser beam direction, by consuming the removed Si species from the deep channel between columns. The Si species ablated off the granulated Si target deposited as Si nanowires or nanoparticles down stream of the Ar flow. Significant decrease in the deposition rate of Si nanostructures has been observed upon the formation of the columnar structures at the target surface.

SYNTHESIS OF ULTRAFINE/NANOSIZE POWDERS OF IRON OXIDES BY PULSED LASER ABLATION AND COLD CONDENSATION

1996 ◽  
Vol 10 (30) ◽  
pp. 1517-1527 ◽  
Author(s):  
S. R. SHINDE ◽  
A. G. BANPURKAR ◽  
K. P. ADHI ◽  
A. V. LIMAYE ◽  
S. B. OGALE ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Vibrating Sample Magnetometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Excimer Laser Ablation ◽  
Nanosize Particles ◽  
Cold Condensation ◽  
Scanning Electron

Ultrafine/nanosize powders of iron oxide have been synthesized from a sintered α- Fe 2 O 3 target by pulsed excimer laser ablation and cold condensation. The influence of target porosity and temperature of condensation on the formation of nanosize particles has been studied. The nanosize powders have been characterized by X-ray diffraction, Mössbauer spectroscopy, vibrating sample magnetometry and scanning electron microscopy. It is shown that the formation of ultrafine/nanosize particles is strongly governed by the target porosity, whereas, the temperature of condensation, over a range from 27°C to −130°C, does not affect the magnetic properties of the nanoparticles.

scholarly journals Facile one-pot synthesis of CuCN by pulsed laser ablation in nitrile solvents and mechanistic studies using quantum chemical calculations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Talshyn Begildayeva ◽  
Ahreum Ahn ◽  
Shreyanka Shankar Naik ◽  
Seung Jun Lee ◽  
Jayaraman Theerthagiri ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Cyano Group ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Binding Energies ◽  
Polymer Materials ◽  
One Pot ◽  
Cu Ions

AbstractBinding energies of different nitrile solvents and their utilization for CuCN formation were investigated through quantum chemical calculations. A pulsed laser ablation in liquid (PLAL) method for CuCN synthesis was developed herein. Initially, the interaction between the pulsed laser and the Cu-target generated Cu-ions and electrons at the point of contact. The laser beam also exhibited sufficient energy to dissociate the bonds of the respective solvents. In the case of acetonitrile, the oxidized Cu-ions bonded with CN− to produce CuCN with a cube-like surface structure. Other nitrile solvents generated spherically-shaped Cu@graphitic carbon (Cu@GC) nanoparticles. Thus, the production of CuCN was favorable only in acetonitrile due to the availability of the cyano group immediately after the fragmentation of acetonitrile (CH3+ and CN−) under PLAL. Conversely, propionitrile and butyronitrile released large amounts of hydrocarbons, which deposited on Cu NPs surface to form GC layers. Following the encapsulation of Cu NPs with carbon shells, further interaction with the cyano group was not possible. Subsequently, theoretical study on the binding energies of nitrile solvents was confirmed by highly correlated basic sets of B3LYP and MP2 which results were consistent with the experimental outcomes. The findings obtained herein could be utilized for the development of novel metal–polymer materials.

scholarly journals Facile One-pot Synthesis of CuCN by Pulsed Laser Ablation in Nitrile Solvents and Mechanistic Studies using Quantum Chemical Calculations

2021 ◽  
Author(s):  
Talshyn Begildayeva ◽  
Ahreum Ahn ◽  
Shreyanka Shankar Naik ◽  
Seung Jun Lee ◽  
Jayaraman Theerthagiri ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Cyano Group ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Binding Energies ◽  
Polymer Materials ◽  
One Pot ◽  
Cu Ions

Abstract Binding energies of different nitrile solvents and their utilization for CuCN formation were investigated through quantum chemical calculations. A pulsed laser ablation in liquid (PLAL) method for CuCN synthesis was developed herein. Initially, the interaction between the pulsed laser and the Cu-target generated Cu-ions and electrons at the point of contact. The laser beam also exhibited sufficient energy to dissociate the bonds of the respective solvents. In the case of acetonitrile, the oxidized Cu-ions bonded with CN− to produce CuCN with a cubic-structure. Other nitrile solvents generated spherically-shaped Cu@graphitic carbon (Cu@GC) nanoparticles. Thus, the production of CuCN was favorable only in acetonitrile due to the availability of the cyano-group immediately after the fragmentation of acetonitrile (CH3+ and CN−) under PLAL. Conversely, propionitrile and butyronitrile released large amounts of hydrocarbons, which deposited on Cu NPs surface to form GC layers. Following the encapsulation of Cu NPs with carbon shells, further interaction with the cyano-group was not possible. Subsequently, theoretical study on the binding energies of nitrile solvents was confirmed by highly correlated basic sets of B3LYP and MP2 which results were consistent with the experimental outcomes. The findings obtained herein could be utilized for the development of novel metal–polymer materials.

Effects of Excimer Laser Ablation on the Surface of Hexagonal Boron Nitride

1990 ◽  
Vol 201 ◽  
Author(s):  
G. L. Doll ◽  
T. A. Perry ◽  
J. A. Sell
Keyword(s):  
Laser Ablation ◽  
Boron Nitride ◽  
Gas Phase ◽  
Hexagonal Boron Nitride ◽  
Cubic Boron Nitride ◽  
Pulsed Laser ◽  
Excimer Laser Ablation ◽  
Induced Changes ◽  
Boron Nitride Films ◽  
Morphology Changes

AbstractThe laser-induced changes in the hexagonal boron nitride targets that are used in the deposition of pulsed laser-deposited cubic boron nitride films are examined. Although the structure of the hexagonal boron nitride in the irradiated areas is unaltered, the surface morphology changes considerably. Boron-rich spheroids were found to cover the irradiated area. Their origin is consistent with the hydrodynamic sputtering of the hexagonal boron nitride targets, and a liberation of nitrogen atoms to the gas phase.

Superconductivity in Nonsymmetric Epitaxial YBa2Cu3O7−δ - PrBa2Cu3O7−δ Superlattices Grown by Pulsed Laser Ablation

1990 ◽  
Vol 191 ◽  
Author(s):  
Douglas H. Lowndes ◽  
David P. Norton ◽  
J. D. Budai ◽  
S. J. Pennycook ◽  
D. K. Christen ◽  
...  
Keyword(s):  
Electronic Structure ◽  
High Temperature ◽  
Laser Ablation ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Proximity Effects ◽  
Excimer Laser Ablation ◽  
Compositional Modulation ◽  
Initial Decrease ◽  
Superlattice Structures

ABSTRACTPulsed KrF (248 nm) excimer laser ablation has been used to grow nonsymmetric epitaxial YBCO/PrBCO superlattices containing 1-, 2-, 3-, 4-, and 8-unit-cell-thick YBCO layers, separated by N-cell-thick insulating PrBCO layers (N = 1–16). The 1×N and 2×N structures exhibit a rapid initial decrease of Tco with increasing PrBCO layer thickness, followed by saturation of Tco at a nonzero value, as the YBCO layers' separation is increased further. The limiting Tco values for 1-, 2-, 3-, 4-, and 8-cell-thick YBCO layers isolated in a PrBCO matrix are ∼19 K, ∼54 K, ∼71 K, ∼80 K, and ∼87 K, respectively. Single-cell-thick YBCO layers are found to be superconducting even when separated by ∼19 nm in a PrBCO matrix. These results are discussed in terms of possible Josephson and/or proximity effects coupling the YBCO layers, and the possibility that PrBCO modifies the electronic structure and depresses Tco in YBCO cells that are immediately adjacent to the PrBCO layers. Finally, high-temperature postannealing studies show that these superlattice structures are stable and that little diffusion occurs along the c-axis direction of compositional modulation.

Fabrication of Permalloy Particles by Pulsed Laser Ablation in Water and Tween 80 Aqueous Solution

2009 ◽  
Vol 1230 ◽  
Author(s):  
Zijie Yan ◽  
Ruqiang Bao ◽  
Cerasela Z Dinu ◽  
Douglas B Chrisey
Keyword(s):  
Aqueous Solution ◽  
Laser Ablation ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Tween 80 ◽  
Spherical Particles ◽  
Distilled Water ◽  
Particle Interactions ◽  
Excimer Laser Ablation ◽  
The Rich

AbstractPermalloy particles were fabricated by pulsed excimer laser ablation in distilled water and Tween 80 aqueous solution with the same laser parameters. Nearly spherical particles and irregular and porous fragments were obtained in water due to rapid condensation and growth of the laser ablated clusters. The products obtained in Tween 80 aqueous solution contained well-shaped spheres but some were laser sintered together via laser-particle interactions. Holes or pits were observed on the surface of some particles, which we consider were caused by laser induced bubbles in the liquid. Our results demonstrate the rich environment ablation in liquids can be for novel particle formation.

Observations on the growth of YBa2Cu3O7-δ thin films on MgO by pulsed-laser ablation

1991 ◽  
Vol 49 ◽  
pp. 1068-1069
Author(s):  
M. Grant Norton ◽  
C. Barry Carter
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Laser Ablation ◽  
Substrate Surface ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Laser Ablation Process ◽  
Deposition Parameters

Pulsed-laser ablation has been widely used to produce high-quality thin films of YBa2Cu3O7-δ on a range of substrate materials. The nonequilibrium nature of the process allows congruent deposition of oxides with complex stoichiometrics. In the high power density regime produced by the UV excimer lasers the ablated species includes a mixture of neutral atoms, molecules and ions. All these species play an important role in thin-film deposition. However, changes in the deposition parameters have been shown to affect the microstructure of thin YBa2Cu3O7-δ films. The formation of metastable configurations is possible because at the low substrate temperatures used, only shortrange rearrangement on the substrate surface can occur. The parameters associated directly with the laser ablation process, those determining the nature of the process, e g. thermal or nonthermal volatilization, have been classified as ‘primary parameters'. Other parameters may also affect the microstructure of the thin film. In this paper, the effects of these ‘secondary parameters' on the microstructure of YBa2Cu3O7-δ films will be discussed. Examples of 'secondary parameters' include the substrate temperature and the oxygen partial pressure during deposition.

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