In-Situ Laser Processing and Microstructural Characteristics of YBa2Cu3O7−δ Thin Films on Si with TiN Buffer Layer

1992 ◽  
Vol 285 ◽  
Author(s):  
P. Tiwari ◽  
T. Zheleva ◽  
J. Narayan
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transition Temperature ◽  
Buffer Layer ◽  
Processing Parameters ◽  
Superconducting Transition ◽  
Epitaxial Relationship ◽  
Ybco Thin Films ◽  
Zero Resistance

ABSTRACTWe have prepared high-quality superconducting YBa2Cu3O7−δ (YBCO) thin films on Si(100) with TiN as a buffer layer using in-situ multitarget deposition system. Both TiN and YBCO thin films were deposited sequentially by KrF excitner laser ( λ = 248 nm ) at substrate temperature of 650°C. Thin films were characterized using X-ray diffraction (XRD), four-point-probe ac resistivity, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Rutherford backscattering (RBS). The TiN buffer layer was epitaxial and the epitaxial relationship was found to be cube on cube with <100> TiN // <100> Si. YBCO thin films on Si with TiN buffer layer showed the transition temperature of 90–92K with Tco (zero resistance temperature) of ∼84K. We have found that the quality of the buffer layer is very important in determining the superconducting transition temperature of the thin film. The effects of processing parameters and the correlation of microstructural features with superconducting properties are discussed indetail.

Processing of Y1Ba2Cu3O7-x Superconducting Thin Films on GaAs Substrates with Double Buffer Layers

1991 ◽  
Vol 236 ◽  
Author(s):  
Sang Yeol Lee ◽  
Quanxi Jia ◽  
Wayne A. Anderson ◽  
David T. Shaw
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
Film Deposition ◽  
Buffer Layers ◽  
Deposition Condition ◽  
Gaas Substrates ◽  
Ybco Thin Films ◽  
Layer Deposition ◽  
Zero Resistance

AbstractHigh temperature superconducting Y1Ba2Cu3O7-x(YBCO) thin films have been grown on GaAs substrates by in situ laser deposition with a double buffer layer of yttrium-stabilized ZrO2 (YSZ)/Si3N4. A barrier layer using a combination of YSZ/Si3N4 was used to grow high quality YBCO thin films without the degradation of the GaAs during YBCO film deposition. Strongly c-axis oriented superconducting YBCO thin films with a zero resistance temperature of 85.5 K and a critical current density of 1.9x103 A/cm2 at 77 K have been obtained. The electrical properties of the YBCO thin films were mainly dependent on YSZ buffer layer deposition condition.

Processing of Y1Ba2Cu3O7−x Superconducting Thin Films on GaAs Substrates with Double Buffer Layers

1991 ◽  
Vol 235 ◽  
Author(s):  
Sang Yeol Lee ◽  
Quanxi Jia ◽  
Wayne A. Anderson ◽  
David T. Shaw
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
Film Deposition ◽  
Buffer Layers ◽  
Deposition Condition ◽  
Gaas Substrates ◽  
Ybco Thin Films ◽  
Layer Deposition ◽  
Zero Resistance

ABSTRACTHigh temperature superconducting Y1Ba2Cu3O7−x(YBCO) thin films have been grown on GaAs substrates by in situ laser deposition with a double buffer layer of yttrium-stabilized ZrO2(YSZ)/Si3N4. A barrier layer using a combination of YSZ/Si3N4 was used to grow high quality YBCO thin films without the degradation of the GaAs during YBCO film deposition. Strongly c-axis oriented superconducting YBCO thin films with a zero resistance temperature of 85.5 K and a critical current density of 1.9×103 A/cm2 at 77 K have been obtained. The electrical properties of the YBCO thin films were mainly dependent on YSZ buffer layer deposition condition.

EPITAXIALLY GROWN YBCO THIN FILMS ON LOW LOSS LaAlO3 SUBSTRATE

1990 ◽  
Vol 04 (05) ◽  
pp. 369-373 ◽  
Author(s):  
Y. Z. ZHANG ◽  
L. LI ◽  
Y. Y. ZHAO ◽  
B. R. ZHAO ◽  
Y. G. WANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Low Loss ◽  
X Ray ◽  
Ybco Thin Films ◽  
Zero Resistance ◽  
Scanning Electron

A planar dc magnetron sputtering device was used to prepare high T c and high J c YBCO thin films. Both single crystal and polycrystal thin films were successfully grown on (100) oriented LaAlO 3 substrates. Zero resistance temperature T c0 = 92.3 K and critical current density J c (0) = 3.82 × 106 A/cm 2 at 77 K was obtained. The films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).

Properties of in-situ laser-pulsed deposited YBCO thin films on MgO with SrTiO3 buffer layer

1996 ◽  
Vol 260 (1-2) ◽  
pp. 111-116 ◽  
Author(s):  
V. Boffa ◽  
T. Petrisor ◽  
L. Ciontea ◽  
U. Gambardella ◽  
S. Barbanera
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
Ybco Thin Films

Epitaxial Relationships of the a-Axis Oriented YBa2Cu3O7-x Thin Films on the PrBa2Cu3O7-xTx Buffered SrTiO3(100) by two Step PLD

1994 ◽  
Vol 341 ◽  
Author(s):  
Gun Yong Sung ◽  
Jeong Dae Suh ◽  
Sahn Nahm
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
Volume Fraction ◽  
Buffer Layers ◽  
Laser Deposition ◽  
Superconducting Properties ◽  
Ybco Thin Film ◽  
Axis Orientation ◽  
Ybco Thin Films ◽  
Zero Resistance

AbstractAn a-axis oriented YBa2Cu3O7-x (YBCO) thin film exhibiting zero resistance at 83 K and critical current density of 7.9x103 A/cm2 at 62 K was obtained on an 180 nm - thick PrBa2Cu3 O7-xx(PBCO) buffered SrTiO3(100) substrate by two step pulsed laser deposition (PLD). The volume fraction of a-axis orientation and the crystallinity(Xmin) of the 150 nm-thick YBCO thin films were increased with increasing the thickness of PBCO buffer layer, which was varied friom 0 nm to 180 nm. It is concluded that the thickness of PBCO buffer layer is one of the important parameters to control the structural and superconducting properties of the a-axis oriented YBCO thin films using the PBCO buffer layers.

Large Area Pulsed Laser Deposition of YBCO Thin Films and Buffer Layers on 3-Inch Wafers

1994 ◽  
Vol 341 ◽  
Author(s):  
M. Lorenz ◽  
H. Hochmuth ◽  
H. Börner ◽  
D. Natusch ◽  
K. Kreher
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
Thickness Distribution ◽  
Buffer Layers ◽  
Large Area ◽  
Promising Technique ◽  
Laser Plume ◽  
Ybco Thin Films ◽  
Epitaxial Oxide

AbstractAn arrangement for large area PLD on 3-inch wafers is proposed. In order to get a homogeneous stoichiometry and thickness distribution and small variations of superconducting properties on the 3-inch diameter, the substrate is foreseen to be rotated and additionally laterally moved up to 45 mm during deposition whereas the laser plume remains fixed.YSZ buffer layers showed thickness homogeneity of 1% within 10 mm, of 4% within 2 inch and of 8% within 3 inch diameter, respectively. For in-situ deposited YBCO thin films on r-plane sapphire with YSZ buffer layer we inductively measured within 3 inch diameter values of the critical temperature Tc(90%) from 85.9 K to 86.7 K and values of the critical current density jc(77 K) from 1 × 106 to 2 × 106 A/cm2. However, up to now the degree of epitaxy of the YBCO thin films on r-plane sapphire with YSZ buffer layer is lower compared to YBCO on MgO(100) as determined by Raman spectroscopy. Nevertheless, large area PLD seems to be a very promising technique for homogeneous coating of 3-inch wafers by epitaxial oxide thin films.

In‐Situ Growth of Superconducting Bi‐Sr‐Ca‐Cu‐O Thin Films by Activated Reactive Co‐evaporation

1989 ◽  
Vol 169 ◽  
Author(s):  
K. Yoshikawa ◽  
T. Satoh ◽  
N. Sasaki ◽  
M. Nakano
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Transition Temperature ◽  
Smooth Surface ◽  
Oxygen Plasma ◽  
In Situ Growth ◽  
Superconducting Properties ◽  
Cooling Conditions ◽  
Zero Resistance

AbstractThe effect of in‐situ cooling conditions on surface roughness and superconducting properties have been studied. Bi‐Sr‐Ca‐Cu‐0 thin films were grown in‐situ on (100) MgO substrates at 700°C by activated reactive co‐evaporation. The films cool‐down in 760 Torr oxygen showed a transition temperature (Tc(onset)) of 100 K and zero resistance temperature (Tc (zero)) of 65 K. Smooth surface was obtained for the sample cooled‐down in oxygen plasma.

Transmission Electron Microscopy studies of texture of Cr underlayer of magnetic recording hard disk

1991 ◽  
Vol 49 ◽  
pp. 580-581
Author(s):  
L. Tang ◽  
G. Thomas ◽  
M. R. Khan ◽  
S. L. Duan
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Magnetic Recording ◽  
Magnetic Thin Films ◽  
Magnetic Films ◽  
Substrate Bias ◽  
Epitaxial Relationship ◽  
Transmission Electron

Cr thin films are often used as underlayers for Co alloy magnetic thin films, such as Co1, CoNi2, and CoNiCr3, for high density longitudinal magnetic recording. It is belived that the role of the Cr underlayer is to control the growth and texture of the Co alloy magnetic thin films, and, then, to increase the in plane coercivity of the films. Although many epitaxial relationship between the Cr underlayer and the magnetic films, such as ﹛1010﹜Co/ {110﹜Cr4, ﹛2110﹜Co/ ﹛001﹜Cr5, ﹛0002﹜Co/﹛110﹜Cr6, have been suggested and appear to be related to the Cr thickness, the texture of the Cr underlayer itself is still not understood very well. In this study, the texture of a 2000 Å thick Cr underlayer on Nip/Al substrate for thin films of (Co75Ni25)1-xTix dc-sputtered with - 200 V substrate bias is investigated by electron microscopy.

Epitaxy and texture analysis of Bi-Sr-Ca-Cu-O thin films on (100) MgO using Transmission Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 68-69
Author(s):  
J. T. Sizemore ◽  
D. G. Schlom ◽  
Z. J. Chen ◽  
J. N. Eckstein ◽  
I. Bozovic ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Critical Currents ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Cell Axis ◽  
Transmission Electron ◽  
Synthesis Procedure

Investigators observe large critical currents for superconducting thin films deposited epitaxially on single crystal substrates. The orientation of these films is often characterized by specifying the unit cell axis that is perpendicular to the substrate. This omits specifying the orientation of the other unit cell axes and grain boundary angles between grains of the thin film. Misorientation between grains of YBa2Cu3O7−δ decreases the critical current, even in those films that are c axis oriented. We presume that these results are similar for bismuth based superconductors and report the epitaxial orientations and textures observed in such films.Thin films of nominally Bi2Sr2CaCu2Ox were deposited on MgO using molecular beam epitaxy (MBE). These films were in situ grown (during growth oxygen was incorporated and the films were not oxygen post-annealed) and shuttering was used to encourage c axis growth. Other papers report the details of the synthesis procedure. The films were characterized using x-ray diffraction (XRD) and transmission electron microscopy (TEM).

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