scholarly journals Effects of Te- and Fe-doping on the superconducting properties in FeySe1−xTex thin films

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Yalin Zhang ◽  
Tong Wang ◽  
Zhihe Wang ◽  
Zhongwen Xing
Keyword(s):  
Thin Films ◽  
Chemical Composition ◽  
Interfacial Structure ◽  
Epitaxial Thin Films ◽  
Superconducting Transition ◽  
Transmission Electron ◽  
Fe Content ◽  
Scanning Transmission ◽  
Microscopy Images ◽  
Deposition Technology

AbstractHigh quality FeySe1−xTex epitaxial thin films have been fabricated on TiO2-buffered SrTiO3 substrates by pulsed laser deposition technology. There is a significant composition deviation between the nominal target and the thin film. Te doping can affect the Se/Te ratio and Fe content in chemical composition. The superconducting transition temperature Tc is closely related to the chemical composition. Fe vacancies are beneficial for the FeySe1−xTex films to exhibit the higher Tc. A 3D phase diagram is given that the optimize range is x = 0.13–0.15 and y = 0.73–0.78 for FeySe1−xTex films. The anisotropic, effective pining energy, and critical current density for the Fe0.72Se0.94Te0.06, Fe0.76Se0.87Te0.13 and Fe0.91Se0.77Te0.23 films were studied in detail. The scanning transmission electron microscopy images display a regular atomic arrangement at the interfacial structure.

scholarly journals Effects of Te- and Fe-doping on the superconducting properties in FeySe1-xTex thin films

2021 ◽  
Author(s):  
Yalin Zhang ◽  
Tong Wang ◽  
Zhihe Wang ◽  
Zhongwen Xing
Keyword(s):  
Thin Films ◽  
Chemical Composition ◽  
Interfacial Structure ◽  
Epitaxial Thin Films ◽  
Superconducting Transition ◽  
Transmission Electron ◽  
Fe Content ◽  
Scanning Transmission ◽  
Microscopy Images ◽  
Deposition Technology

Abstract High quality FeySe1−xTex epitaxial thin films have been fabricated on TiO2-buffered SrTiO3 substrates by pulsed laser deposition technology. There is a significant composition deviation between the nominal target and the thin film. Te doping can affect the Se/Te ratio and Fe content in chemical composition. The superconducting transition temperature Tc is closely related to the chemical composition. Fe vacancies are beneficial for the FeySe1−xTex films to exhibit the higher Tc. A 3D phase diagram is given that the optimize range is x = 0.13 − 0.15 and y = 0.73 − 0.78 for FeySe1−xTex films. The anisotropic, effective pining energy and critical current density for the Fe0.72Se0.94Te0.06, Fe0.76Se0.87Te0.13 and Fe0.91Se0.77Te0.23 samples were studied in detail. The scanning transmission electron microscopy images display a regular pattern without obviously scale defects at the interfacial structure.

Deposition Rate Effect on Critical Thickness of BaTiO3 Epitaxial Thin Film Grown on SrTiO3 (001)

2007 ◽  
Vol 1034 ◽  
Author(s):  
Masanori Kawai ◽  
Daisuke Kan ◽  
Seiichi Isojima ◽  
Hiroki Kurata ◽  
Seiji Isoda ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Deposition Rate ◽  
Critical Thickness ◽  
High Deposition Rate ◽  
Misfit Dislocations ◽  
Epitaxial Thin Films ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Scanning Transmission

AbstractBaTiO3/SrTiO3(001) epitaxial thin films were prepared at various growth rates by pulsed laser deposition, and their heterostructures were evaluated by synchrotron x-ray diffraction measurements and cross-sectional scanning transmission electron microscopy observations. In a film grown at a low deposition rate (0.01 nm/s), misfit dislocations are found near the interface and a fully relaxed BaTiO3 thin film grows epitaxially on the substrate. On the other hand, a film grown at a high deposition rate (0.04 nm/s) consists of strained and relaxed BaTiO3 lattices. Our results showed that the critical thickness of BaTiO3/SrTiO3(001) epitaxial thin films can be controlled by the deposition rate and that the critical thickness increases with increasing the deposition rate, and by adjusting the deposition rate we were able to prepare epitaxial thin films consisting of fully strained BaTiO3, partially strained BaTiO3 or fully relaxed BaTiO3. We have also achieved the growth controlling of BaTiO3 thin films on SrTiO3(001) substrates with SrRuO3 bottom electrode layer.

Effect of the deposition rate on thin films of CuZnAl obtained by thermal evaporation

2010 ◽  
Vol 1276 ◽  
Author(s):  
L. López-Pavón ◽  
E. López-Cuellar ◽  
A. Torres-Castro ◽  
C. Ballesteros ◽  
C. José de Araújo
Keyword(s):  
Thin Films ◽  
Chemical Composition ◽  
Deposition Rate ◽  
Thermal Evaporation ◽  
Deposition Process ◽  
Significant Loss ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Evaporation Source

AbstractThermal evaporation is used to deposit thin films of CuZnAl on silicon substrates. For this purpose, a CuZnAl shape memory alloy is used as evaporation source. The chemical composition and the phases present in the films are evaluated at two different deposition rates: 7 and 0.2 Å/s. The thin films are heat treated to promote the diffusion of the elements and characterized by X-ray Diffraction, Energy Dispersive X-ray Spectroscopy and Scanning Transmission Electron Microscopy (STEM). It is shown that the chemical composition of the thin films is significantly different to that of the CuZnAl alloy used as evaporation source. Moreover, the films produced at 7 Å/s show a significant loss of Zn, contrary to the results obtained using a deposition rate of 0.2 Å/s. It is also observed that the composition varies across the thickness of the film, suggesting that the various alloying elements are evaporated at different rates during the deposition process. Finally the predominant phases present in the films belong to the AlxCuy family.

Rocking Beam Microarea Diffraction Applied to Metallic thin Films

1976 ◽  
Vol 34 ◽  
pp. 396-397
Author(s):  
R. H. Geiss
Keyword(s):  
Thin Films ◽  
Electron Diffraction ◽  
Small Area ◽  
Objective Lens ◽  
Electron Optics ◽  
Metallic Thin Films ◽  
Transmission Electron Diffraction ◽  
Transmission Electron ◽  
Sample Height ◽  
Scanning Transmission

The theory and practical limitations of micro area scanning transmission electron diffraction (MASTED) will be presented. It has been demonstrated that MASTED patterns of metallic thin films from areas as small as 30 Åin diameter may be obtained with the standard STEM unit available for the Philips 301 TEM. The key to the successful application of MASTED to very small area diffraction is the proper use of the electron optics of the STEM unit. First the objective lens current must be adjusted such that the image of the C2 aperture is quasi-stationary under the action of the rocking beam (obtained with 40-80-160 SEM settings of the P301). Second, the sample must be elevated to coincide with the C2 aperture image and its image also be quasi-stationary. This sample height adjustment must be entirely mechanical after the objective lens current has been fixed in the first step.

Electron Microscopy Studies of The Chemistry And Microstructure of BaF2 / YBa2Cu3O7-x Thin Films

1994 ◽  
Vol 52 ◽  
pp. 796-797
Author(s):  
J. L. Lee ◽  
C. A. Weiss ◽  
R. A. Buhrman ◽  
J. Silcox
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Transmission Electron Microscope ◽  
Atomic Scale ◽  
Island Growth ◽  
Multilayer Systems ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Mgo Substrate

BaF2 thin films are being investigated as candidates for use in YBa2Cu3O7-x (YBCO) / BaF2 thin film multilayer systems, given the favorable dielectric properties of BaF2. In this study, the microstructural and chemical compatibility of BaF2 thin films with YBCO thin films is examined using transmission electron microscopy and microanalysis. The specimen was prepared by using laser ablation to first deposit an approximately 2500 Å thick (0 0 1) YBCO thin film onto a (0 0 1) MgO substrate. An approximately 7500 Å thick (0 0 1) BaF2 thin film was subsequendy thermally evaporated onto the YBCO film.Images from a VG HB501A UHV scanning transmission electron microscope (STEM) operating at 100 kV show that the thickness of the BaF2 film is rather uniform, with the BaF2/YBCO interface being quite flat. Relatively few intrinsic defects, such as hillocks and depressions, were evident in the BaF2 film. Moreover, the hillocks and depressions appear to be faceted along {111} planes, suggesting that the surface is smooth and well-ordered on an atomic scale and that an island growth mechanism is involved in the evolution of the BaF2 film.

Determination of Nanocluster Sizes from Dark-Field Scanning Transmission Electron Microscopy Images

2008 ◽  
Vol 112 (6) ◽  
pp. 1759-1763 ◽  
Author(s):  
Norihiko L. Okamoto ◽  
Bryan W. Reed ◽  
Shareghe Mehraeen ◽  
Apoorva Kulkarni ◽  
David Gene Morgan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Scanning Transmission Electron Microscopy ◽  
Dark Field ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Microscopy Images

scholarly journals Donald William Pashley. 21 April 1927 — 16 May 2009

2010 ◽  
Vol 56 ◽  
pp. 317-340 ◽  
Author(s):  
Bruce A. Joyce ◽  
Michael J. Stowell
Keyword(s):  
Thin Films ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Film Growth ◽  
Epitaxial Thin Films ◽  
Disorder Effects ◽  
Transmission Electron ◽  
Innovative Materials ◽  
Low Dimensional

Donald William (Don) Pashley was one of the most innovative materials scientists of his generation. He was distinguished for his electron diffraction and transmission electron microscope studies of epitaxial thin films, especially for in situ investigations, work that contributed enormously to our understanding of film growth processes. He pioneered the use of moiré patterns to reveal dislocations and other defects. He also made important contributions to long-range disorder effects on semiconductor surfaces and to the structure of low-dimensional semiconductor systems.

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