YBa2Cu3O7−x THIN FILMS GROWN ON SAPPHIRE WITH EPITAXIAL YTTRIA-STABILIZED ZrO2 BUFFER LAYER

1993 ◽  
Vol 07 (27) ◽  
pp. 1741-1746
Author(s):  
S.F. XU ◽  
Y.J. TIAN ◽  
H.B. LÜ ◽  
Y.L. ZHOU ◽  
Z.H. CHEN ◽  
...  

We have successfully fabricated high-quality YBa 2 Cu 3 O 7−x (YBCO) thin films grown on sapphire with epitaxial Yttria-Stabilized ZrO 2 (YSZ) buffer layer by pulsed laser deposition. X-ray diffraction and Auger depth profile were used to characterize these thin films. The values of zero-resistance temperature Tco and critical current density J c (at 77 K) of c-axis oriented YBCO thin film with 500 Å-YSZ buffer layer were 91 K and 2.2×106 A/cm 2, respectively. The Auger depth profile showed that no obvious diffusion occurred between the buffer layer and the YBCO film. The influence of substrate temperature and thickness of buffer layer has been investigated.

1994 ◽  
Vol 9 (6) ◽  
pp. 1337-1342
Author(s):  
Takashi Hase ◽  
Ryusuke Kita ◽  
Kenichi Kawaguchi ◽  
Takeshi Koga ◽  
Tadataka Morishita

YBa2Cu3O7−x (YBCO) superconducting thin films that show no x-ray diffraction peaks due to any other non-superconducting phases have been synthesized by annealing Y-Ba-Cu-O amorphous precursors at 750 °C. The Y-Ba-Cu-O precursors have been fabricated by oxidizing Y-Ba-Cu metallic precursors coevaporated from Y, Ba, and Cu metallic sources under ultrahigh vacuum conditions. Crystallization behavior from the Y-Ba-Cu-O precursor to YBCO films drastically depends on an oxidation temperature for the Y-Ba-Cu metallic precursor. YBCO thin film synthesized from the precursor oxidized at an optimum temperature shows a zero resistance temperature of over 80 K and a very smooth surface.


2000 ◽  
Vol 14 (25n27) ◽  
pp. 2646-2651
Author(s):  
F. RICCI ◽  
F. CARILLO ◽  
F. LOMBARDI ◽  
F. MILETTO GRANOZIO ◽  
U. SCOTTI DI UCCIO ◽  
...  

(110) and (103) YBa 2 Cu 3 O 7 films have been grown onto exact and vicinal (110) SrTiO 3 substrates, and on vicinal (110) MgO substrates with a SrTiO 3 buffer layer. The samples are carefully characterised by reciprocal space mapping with x-ray diffraction, in order to investigate the features of the typical double domain of (110) and (103) YBa 2 Cu 3 O 7 structure. It is demonstrated that vicinal cut substrates allow to select one film/substrate epitaxial relation. The growth properties of these thin films deposited on vicinal surfaces are discussed.


1990 ◽  
Vol 04 (05) ◽  
pp. 369-373 ◽  
Author(s):  
Y. Z. ZHANG ◽  
L. LI ◽  
Y. Y. ZHAO ◽  
B. R. ZHAO ◽  
Y. G. WANG ◽  
...  

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).


2012 ◽  
Vol 510-511 ◽  
pp. 89-97
Author(s):  
G.H. Tariq ◽  
M. Anis-ur-Rehman

To overcome the naturally existing Schottky barrier problem between p-CdTe and any metal, an intermediate semiconductor thin buffer layer is a better choice prior to the final metallization for contact. Among many investigated back contact materials the ZnTe is suitable as a buffer layer. ZnTe thin films were deposited onto glass substrates by the thermal evaporation technique under vacuum ~2×10-5mbar. Undoped ZnTe thin films are highly resistive, extrinsic doping of Cu was made to improve the electrical conductivity. Films were doped by immersing in Cu NO32.5H2O solutions for Cu doping. To optimize the growth parameters the prepared films were characterized using various techniques. The structural analysis of these films was performed by X-ray diffraction (XRD) technique and optical transmission. X-ray diffraction identified the phases present in these films and also observed that the prepared films were polycrystalline. Also the spectral dependence of absorption coefficient was determined from spectrophotometer. Energy band gap index were calculated from obtained optical measurements data.


1993 ◽  
Vol 07 (01) ◽  
pp. 19-23 ◽  
Author(s):  
W. A. LUO ◽  
Y. Q. TANG ◽  
Y. Z. CHEN ◽  
I. N. CHAN ◽  
K. Y. CHEN ◽  
...  

In this letter, we describe results obtained via laser ablation to fabricate Tl 2 Ba 2 Ca 2 Cu 3- O 10 superconducting thin films using a two-step process. We found that the zero-resistance temperatures are up to 121 K, while the onset temperatures are up to 125 K. The T c and J c are mainly determined by a non-contact new technique for high-T c films. The typical critical current density, J c , is about 106 A/cm 2 at 77 K. X-ray diffraction showed that the superconducting thin films are nearly single 2223 phase and are highly oriented.


1987 ◽  
Vol 01 (02) ◽  
pp. 571-574
Author(s):  
Jia-qi Zheng ◽  
Guo-guang Zheng ◽  
Dong-qi Li ◽  
Wei Wang ◽  
Jin-min Xue ◽  
...  

Y-Ba-Cu-O thin films are deposited onto severval kinds of substrates by electron beam evaporating in a high vacuum system. After the heat treatment at 850–890°c for 1hr the Y-Ba-Cu-O films on the BaF2 substrates show superconducting behaviors with the midpoint Tc around 87K and zero resistance temperature at 77K. The composition and stucture analysis of these films have been studied by AES, XRFS and x-ray diffraction.


2021 ◽  
Vol 54 (1) ◽  
Author(s):  
Claudia Cancellieri ◽  
Daniel Ariosa ◽  
Aleksandr V. Druzhinin ◽  
Yeliz Unutulmazsoy ◽  
Antonia Neels ◽  
...  

Thin films generally contain depth-dependent residual stress gradients, which influence their functional properties and stability in harsh environments. An understanding of these stress gradients and their influence is crucial for many applications. Standard methods for thin-film stress determination only provide average strain values, thus disregarding possible variation in strain/stress across the film thickness. This work introduces a new method to derive depth-dependent strain profiles in thin films with thicknesses in the submicrometre range by laboratory-based in-plane grazing X-ray diffraction, as applied to magnetron-sputtering-grown polycrystalline Cu thin films with different thicknesses. By performing in-plane grazing diffraction analysis at different incidence angles, the in-plane lattice constant depth profile of the thin film can be resolved through a dedicated robust data processing procedure. Owing to the underlying intrinsic difficulties related to the inverse Laplace transform of discrete experimental data sets, four complementary procedures are presented to reliably extract the strain depth profile of the films from the diffraction data. Surprisingly, the strain depth profile is not monotonic and possesses a complex shape: highly compressive close to the substrate interface, more tensile within the film and relaxed close to the film surface. The same strain profile is obtained by the four different data evaluation methods, confirming the validity of the derived depth-dependent strain profiles as a function of the film thickness. Comparison of the obtained results with the average in-plane stresses independently derived by the standard stress analysis method in the out-of-plane diffraction geometry validates the solidity of the proposed method.


2000 ◽  
Vol 14 (25n27) ◽  
pp. 2731-2736 ◽  
Author(s):  
M. BINDI ◽  
F. FUSO ◽  
N. PUCCINI ◽  
E. ARIMONDO ◽  
A. TAMPIERI ◽  
...  

Correctly c-axis oriented HgBa 2 CaCu 2 O 6+δ thin films have been produced on (100) MgO single crystal substrates and characterized. Pulsed laser deposition has been exploited to deposit Hg-free Re-doped precursor which then underwent synthesis in evacuated and sealed quartz tubes. X-ray diffraction pattern of the precursor target shows the expected composition of oxides. Scanning electron microscopy analysis have been performed on the surface of the precursor film. Hg-1212 films have been analyzed by θ-2θ Bragg-Brentano X-ray diffractometry. The patterns show little contributions in composition of Hg-1223 phase. The films exhibit a transition temperature >120 K with zero-resistance at around 115 K.


2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744054 ◽  
Author(s):  
Zhangpeng Shao ◽  
Chengwu Shi ◽  
Junjun Chen ◽  
Yanru Zhang

SnS thin films with gear-like sheet appearance were successfully prepared by close-spaced vacuum thermal evaporation using SnS powders as a source. The influence of substrate temperature on the surface morphology, chemical composition, crystal structure and optical property of SnS thin films was investigated by scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction and ultraviolet–visible–near infrared spectroscopy. The results revealed that serration architecture appeared obviously in the edge of the SnS sheet and the strongest peak at 2[Formula: see text]=31.63[Formula: see text] was broadened and many shoulder peaks were observed with increasing substrate temperature. The atomic ratio of Sn to S increased from 1:1.08 to 1:1.20, the grain size became slightly smaller and the optical absorption edge had a blueshift in the SnS thin film with decreasing substrate temperature.


1989 ◽  
Vol 169 ◽  
Author(s):  
Ashok Kumar ◽  
L. Ganapathi ◽  
J. Narayan

AbstractWe have prepared highly textured superconducting thin films from Bi1.5pb0.5Ca3Sr2Cu4Ox (2324) on (100) YS-ZrO2 (Yttria stabilized zirconia) and Bi1.5Pb0.5Ca2Sr2Cu3°x (2223) on LaAlC-3 (100) and MgO (100) substrates at 650°C by pulsed laser ablation method.These films showed 2212 type of phase of the (BiPb)2(Ca,Sr)n+1CunO2n+4+5 family with onset transition temperature ( Tc ) ~ 110 K, confirming our earlier observations of 110 K superconductivity in a n = 2 bulk material. Thin films deposited from 2324 bulk target on YS-Z1O2 showed zero resistance temperature (Tco ) of 68 K but post annealing for one hour at 400°C in oxygen improved Tco from 68 K to 82 K. Thin films from 2223 target on LaAlO3 ( 100 ) and MgO ( 100 ) exhibited a Tco of 65 K and 74 K respectively while onset remained the same at 110 K. Further annealing at 400°C for one hour in oxygen did not show any improvement in Tco. X-ray diffraction (XRD), scanning electron microscopy (SEM) and Rutherford backscattering (RBS) channeling studies were performed on these films for correlation between crystal structure, microstructure and superconducting properties. X-ray diffraction patterns indicated 2212 type phase with a= 5.39 Å and c=30.76 Å; preferential orientation of c-axis perpendicular to the substrate was observed. The lattice parameter and x-ray diffraction patterns were found to be invariant with annealing treatments.


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