Computer Simulation of Pulsed Laser Ablation for YBaCuO Superconducting Films

1990 ◽  
Vol 191 ◽  
Author(s):  
Toshiyuki Nakamiya ◽  
Kenji Ebihara ◽  
P. K. John ◽  
B. Y. Tong
Keyword(s):  
Thin Films ◽  
Excimer Laser ◽  
Laser Energy ◽  
Pulsed Laser ◽  
The Finite Element Method ◽  
High Tc ◽  
One Dimensional ◽  
Incident Laser Energy ◽  
Krf Excimer Laser ◽  
Pulsed Laser Irradiation

ABSTRACTThe dynamics of melting and ablation of high Tc YBa2Cu3O7-x superconducting thin films flashed by a pulsed KrF excimer laser(λ=248nm) or a pulsed Nd-YAG laser (λ =1.06μ m) were studied numerically. The fundamental model during a pulsed laser irradiation was a one-dimensional heat conduction equation. The finite element method was applied to solve the equation including the temperature dependence of the thermal conductivity of YBaCuO thin films. In addition, the microstructure of YBa2Cu3O7-x bulk(l.5mm thick) flashed by a pulsed XeCl excimer laser (λ =308nm) was investigated by scanning electron microscopy (SEM) in order to estimate the threshold incident laser energy density for surface melting and ablation. The good agreements between the numerical calculations and the experimental results were obtained.

Carbon nitride thin films prepared by nitrogen ion assisted pulsed laser deposition of graphite using KrF excimer laser

1999 ◽  
Vol 339 (1-2) ◽  
pp. 38-43 ◽  
Author(s):  
Kazuhiro Yamamoto ◽  
Yoshinori Koga ◽  
Shuzo Fujiwara ◽  
Fumio Kokai ◽  
Jacob I. Kleiman ◽  
...  
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Excimer Laser ◽  
Carbon Nitride ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Nitrogen Ion ◽  
Krf Excimer Laser

Synthesis and Characterization of Ferroelectric Thin Films by KrF Excimer Laser Ablation for Memory Applications

1998 ◽  
Vol 526 ◽  
Author(s):  
Ashok Kumar ◽  
M.R. Alam
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Excimer Laser ◽  
Lead Zirconate Titanate ◽  
Laser Energy ◽  
Ferroelectric Thin Film ◽  
Lead Zirconate ◽  
Test System ◽  
Excimer Laser Ablation ◽  
Krf Excimer Laser

AbstractPb(ZrxTi1-x)O3 (lead zirconate titanate or PZT) ferroelectric thin film capacitors are of considerable interest for the realization of memory devices such as nonvolatile random access memories (NVRAMs). The PZT capacitors were prepared on platinized silicon Pt/(100)Si using conducting oxide LaxSr1-xCoO3 (lanthanum strontium cobalt oxide or LSCO) as electrodes. The PZT and LSCO thin films were deposited by the KrF excimer laser ablation technique. The optimum preparation conditions such as oxygen pressure, laser energy influence and substrate temperature were investigated. The PZT and LSCO films grown on Pt/(100)Si are polycrystalline. The crystallographic properties of the films were determined using X-ray diffractometer (XRD) method. The electrical characterizations of the films including hysteresis loop, fatigue, and retention properties were determined by the RT66A Standardized Ferroelectric Test System.

Mechanical properties of pulsed laser-deposited hydroxyapatite thin films for applications in biomedical implants

2002 ◽  
Vol 750 ◽  
Author(s):  
Hyunbin Kim ◽  
Yogesh K. Vohra ◽  
William R. Lacefield ◽  
Renato P. Camata
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Energy Density ◽  
Laser Energy ◽  
Pulsed Laser ◽  
X Ray Diffraction ◽  
X Ray ◽  
Krf Excimer Laser ◽  
Average Size ◽  
Substrate Temperatures

ABSTRACTWe have obtained nanostructured hydroxyapatite thin films on titanium alloy substrates by pulsed laser deposition. Deposition was carried out using a KrF excimer laser (248 nm) with the energy density of 4 – 7 J/cm2 at substrate temperatures in the 550°C - 650°C range. The crystallinity of the coatings was probed by X-ray diffraction. Phase transitions from hydroxyapatite to other calcium phosphate compounds were observed with varying the substrate temperature during the growth process. Scanning electron microscopy revealed thin films made up of partially sintered nanoscale grains. The average size of nanoscale grains increased significantly with film thickness, suggesting a growth mechanism involving the coalescence of nanoscale grains. As the laser energy density increases, the hydroxyapatite crystallites in the coatings are oriented preferentially along the c-axis perpendicular to the substrate. Mechanical properties of the highly c-axis oriented coatings such as hardness and Young's modulus were studied by using nanoindentation technique.

PULSED LASER IRRADIATION OF NICKEL THIN FILMS ON SILICON

1983 ◽  
Vol 44 (C5) ◽  
pp. C5-449-C5-454 ◽  
Author(s):  
P. Baeri ◽  
M. G. Grimaldi ◽  
E. Rimini ◽  
G. Celotti
Keyword(s):  
Thin Films ◽  
Laser Irradiation ◽  
Pulsed Laser ◽  
Nickel Thin Films ◽  
Pulsed Laser Irradiation

Short pulsed laser irradiation of amorphous germanium thin films

1982 ◽  
Vol 97 (1) ◽  
pp. 1-7 ◽  
Author(s):  
R.K. Sharma ◽  
S.K. Bansal ◽  
R. Nath ◽  
G.P. Srivastava
Keyword(s):  
Thin Films ◽  
Laser Irradiation ◽  
Pulsed Laser ◽  
Amorphous Germanium ◽  
Pulsed Laser Irradiation

scholarly journals Preparation and Properties of Superconducting thin Films by Excimer Laser Ablation

1990 ◽  
Vol 191 ◽  
Author(s):  
Michael E. Geusic ◽  
Alan F. Stewart ◽  
Larry R. Pederson ◽  
William J. Weber ◽  
Kenneth R. Marken ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Excimer Laser ◽  
Laser Energy ◽  
Substrate Surface ◽  
Xrd Analysis ◽  
Zero Field ◽  
Superconducting Transition ◽  
X Ray Diffraction ◽  
Excimer Laser Ablation

ABSTRACTExcimer laser ablation with an in situ heat treatment was used to prepare high quality superconducting YBa2Cu3O7−x thin films on (100)-SrTiO3 and (100)-LaAlO3 substrates. A pulsed excimer laser (XeCl; 308 nm) was used to ablate a rotating, bulk YBa2Cu3O7−x target at a laser energy density of 2–3 J/cm2. Based on four-probe dc resistance measurements, the films exhibited superconducting transition temperatures (Tc, midpoint) of 88 and 87K with 2K (90–10%) transition widths for SrTiO3 and LaAlO3, respectively. Transport critical current densities (Jc) measured at 77K were 2 × 106 and 1 × 106 A/cm2 in zero field for SrTiO3 and LaAlO3, respectively. X-ray diffraction (XRD) analysis showed the films to be highly oriented, with the c-axis perpendicular to the substrate surface.

Epitaxial Growth of AlN Thin Films on Silicon and Sapphire by Pulsed Laser Deposition

1995 ◽  
Vol 395 ◽  
Author(s):  
R.D. Vispute ◽  
H. Wu ◽  
K. Jagannadham ◽  
J. Narayan
Keyword(s):  
Thin Films ◽  
Electrical Resistivity ◽  
Pulsed Laser Deposition ◽  
Laser Energy ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Breakdown Field ◽  
Transmission Electron ◽  
Uv Visible ◽  
Relationship Of

ABSTRACTAIN thin films have been grown epitaxially on Si(111) and Al2O3(0001) substrates by pulsed laser deposition. These films were characterized by FTIR and UV-Visible, x-ray diffraction, high resolution transmission electron and scanning electron microscopy, and electrical resistivity. The films deposited on silicon and sapphire at 750-800°C and laser energy density of ∼ 2 to 3J/cm2 are epitaxial with an orientational relationship of AIN[0001]║ Si[111], AIN[2 110]║Si[011] and AlN[0001]║Al2O3[0001], AIN[1 2 1 0]║ Al2O3[0110] and AIN[1010] ║ Al2O3[2110]. The both AIN/Si and AIN/Al2O3 interfaces were found to be quite sharp without any indication of interfacial reactions. The absorption edge measured by UV-Visible spectroscopy for the epitaxial AIN film grown on sapphire was sharp and the band gap was found to be 6.1eV. The electrical resistivity of the films was about 5-6×l013Ω-cm with a breakdown field of 5×106V/cm. We also found that the films deposited at higher laser energy densities ≥10J/cm2 and lower temperatures ≤650°C were nitrogen deficient and containing free metallic aluminum which degrade the microstructural, electrical and optical properties of the AIN films

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