Improved Epitaxy and Surface Morphology in YBa2Cu3Oy Thin Films Grown on Double Buffered Si Wafers

2003 ◽  
Vol 17 (18n20) ◽  
pp. 3695-3697 ◽  
Author(s):  
J. Gao ◽  
L. Kang ◽  
H. Y. Wong ◽  
Y. L. Cheung ◽  
J. Yang

Highly epitaxial thin films of YBCO have been obtained on silicon wafers using a Eu 2 CuO 4/ YSZ (yttrium-stabilized ZrO 2) double buffer. Our results showed that application of such a double buffer can significantly enhance the epitaxy of grown YBCO. It also leads to an excellent surface morphology. The average surface roughness was found less than 5 nm in a large range. The results of X-ray small angle reflection and positron spectroscpy demonstrate a very clear and flat interface between YBCO and buffer layers. The Eu 2 CuO 4/ YSZ double buffer could be promising for coating high-TC superconducting films on various reactive substrates.

2013 ◽  
Vol 1507 ◽  
Author(s):  
Ryosuke Yamauchi ◽  
Geng Tan ◽  
Daishi Shiojiri ◽  
Nobuo Tsuchimine ◽  
Koji Koyama ◽  
...  

ABSTRACTWe examined the influence of momentary annealing on the nanoscale surface morphology of NiO(111) epitaxial thin films deposited on atomically stepped sapphire (0001) substrates at room temperature in O2 at 1.3 × 10−3 and 1.3 × 10−6 Pa using a pulsed laser deposition (PLD) technique. The NiO films have atomically flat surfaces (RMS roughness: approximately 0.1–0.2 nm) reflecting the step-and-terrace structures of the substrates, regardless of the O2 deposition pressure. After rapid thermal annealing (RTA) of the NiO(111) epitaxial film deposited at 1.3 × 10−3 Pa O2, a periodic straight nanogroove array related to the atomic steps of the substrate was formed on the film surface for 60 s. In contrast, the fabrication of a transient state in the nanogroove array formation was achieved with RTA of less than 1 s. However, when the O2 atmosphere during PLD was 1.3 × 10−6 Pa, random crystal growth was observed and resulted in a disordered rough surface nanostructure after RTA.


2007 ◽  
Vol 1040 ◽  
Author(s):  
Hiroaki Yokoo ◽  
Naoki Wakiya ◽  
Naonori Sakamoto ◽  
Takato Nakamura ◽  
Hisao Suzuki

AbstractWe have grown indium nitride (InN) films using In buffer layer on an a-plane sapphire substrate under atmospheric pressure by halide CVD (AP-HCVD). Growth was carried out by two steps: deposition In buffer layer at 900 °C and subsequent growth of InN layer at 650 °C. In order to compare, we also grown InN films on an a-plane sapphire. The InN films are investigated on crystal quality, surface morphology and electrical property using high-resolution X-ray diffraction (HR-XRD), X-ray pole figure, scanning electron microscope (SEM), Hall measurement. The results show that the crystal quality, surface morphology and electrical property of InN films are improved by using In buffer layer.


1984 ◽  
Vol 11 (3) ◽  
pp. 237-241 ◽  
Author(s):  
M. El-Shabasy ◽  
L. Pogány ◽  
G. Konczos ◽  
E. Hajtó ◽  
B. Szikora

The adhesion of evaporated or sputtered thin films to substrates is one of the most important characterising parameters in their fabrication. It is a conventional method to scratch the films using a stylus and evaluate the shearing stress, which is proportional to the energy of adhesion. For the evaluation it is necessary to determine the so-called critical load and the profile of the scratch.The aim during this experimental work was to find a method to evaluate the scratch profile from the X-ray-line profile and SEM pictures. From SEM pictures, the lateral dimensions and surface morphology of the scratches were studied. The thickness was also studied from X-ray-line profiles.In this paper the thickness profile measuring method and the conclusion for the scratch method are discussed.


2012 ◽  
Vol 488-489 ◽  
pp. 76-81 ◽  
Author(s):  
Subramani Shanmugan ◽  
Mutharasu Devarajan ◽  
Kamarulazizi Ibrahim

Sb layered Te/Cd thin films have been prepared by using Stacked Elemental Layer (SEL) method. The presence of mixed phases (CdTe and Sb2Te3) in the films was confirmed by the x-ray diffraction technique. The calculated structural parameters demonstrated the feasibility of Sb doping via SEL method. The topographical and electrical studies of the synthesized thin films depicted the influence of Sb on both surface morphology and conductivity. The values of conductivity of the annealed films were in between 2 x 10-3 and 175 x 10-2 Scm-2. A desired chemical composition of films was confirmed from spectrum shape analysis using energy dispersive x-ray.


1989 ◽  
Vol 169 ◽  
Author(s):  
K.M. Hubbard ◽  
P.N. Arendt ◽  
D.R. Brown ◽  
D.W. Cooke ◽  
N.E. Elliott ◽  
...  

AbstractThin films of the Tl‐based superconductors often have relatively poor properties because of film/substrate interdiffusion which occurs during the anneal. We have therefore investigated the use of BaF2 as a diffusion barrier. TICaBaCuO thin films were deposited by dc magnetron sputtering onto MgO <100> substrates, both with and without an evaporation‐deposited BaF2 buffer layer, and post‐annealed in a Tl over‐pressure. Electrical properties of the films were determined by four‐point probe analysis, and compositions were measured by ion‐backscattering spectroscopy. Structural analysis was performed by X‐ray diffraction and scanning electron microscopy. The BaF2 buffer layers were found to significantly improve the properties of the TICaBaCuO thin films.


1989 ◽  
Vol 33 ◽  
pp. 145-151
Author(s):  
M. O. Eatough ◽  
D. S. Ginley ◽  
B. Morosin

AbstractSuperconducting thin films (0.3-0.7μm) in the TI-Ca-Ba-Cu-0 system have been prepared on various single crystal substrates by sequential electron beam evaporation followed by appropriate sintering and annealing. Oxygen-annealed films show Tc as high as 110K and critical current densities to 600,000 A/cm2. X-ray diffraction analyses of these films show predominantly the Tl2Ca2Ba2Cu2O10 phase (c-parameter near 36Å), but some also contain up to 50 at% of the Tl2CaBa2Cu2O8 phase (c-parameter near 30Å). The complete absence of hkl reflections other than 00I demonstrates the highly oriented nature of the films as well as the absence of other Tl phases. The diffraction peaks are noticeably broader for the 36Å phase than for the 30Å phase. For a 0.7μm film such broadening is consistent with coherent sizes along the c-axis of 1200 - 1400Å and 500Å, respectively, for the 30Å and 36Å phases, and of strain values near 1.4-1.8 x 10-3 for both phases.


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