Growth of epitaxial CeO2 buffer layers by polymer assisted deposition

2012 ◽  
Vol 1449 ◽  
Author(s):  
A. Calleja ◽  
R. B. Mos ◽  
P. Roura ◽  
J. Farjas ◽  
J. Arbiol ◽  
...  
Keyword(s):  
Film Growth ◽  
Polymer Network ◽  
Coated Conductors ◽  
Buffer Layers ◽  
X Ray Diffraction ◽  
Interesting Possibility ◽  
Dta Analysis ◽  
Metalorganic Decomposition ◽  
Metal Polymer ◽  
Polymer Species

ABSTRACTPolymer assisted deposition (PAD) has been reported as a novel CSD approach for thin film growth with improved homogeneity and long stability by forming a metal polymer species. It also offers the interesting possibility of having a library of PAD solutions for each precursor metal and obtaining the required composition by simple mixing. Another potential advantage is the increase in thickness since mechanical stresses are expected to be alleviated during shrinkage in the metalorganic decomposition by the metal-polymer network.Cerium oxide films on YSZ single crystals were grown from water-based solutions containing cerium nitrate, polyethyleneimine and complexing EDTA, in order to explore the benefits of using the PAD approach for growing buffer layers in coated conductors. An ultrafiltration step was performed to remove the non-coordinated species in solution. The degree of purification and efficiency in the cerium recovery was investigated by different techniques. TGA-DTA analysis was used to provide guidance to the best thermal profiles in different atmospheres and specially to diminish the adverse effects of exothermic events during decomposition. Microstructural evolution was tracked by AFM and TEM, while epitaxial fraction was followed by X-ray diffraction. The results show the high importance of choosing the proper atmosphere and the need for tuning of heating ramps to obtain dense, flat and epitaxial ceria films by PAD.

Characterisation of YSZ Layers Deposited on Y2O3 Buffered Textured Tapes for Coated Conductors

2014 ◽  
Vol 787 ◽  
pp. 425-430
Author(s):  
Yu Dong Xia ◽  
Jie Xiong ◽  
Fei Zhang ◽  
Yan Xue ◽  
Kai Hu ◽  
...  
Keyword(s):  
Coated Conductors ◽  
Buffer Layers ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
X Ray ◽  
Atomic Force ◽  
Deposition Parameters ◽  
Out Of Plane ◽  
Textured Tapes ◽  
Moving Speed

Yttria-stabilized zirconia (YSZ) films were deposited on Y2O3/Ni-5at.%W substrates serving as the barrier layers for coated conductors by reel-to-reel direct-current (D.C.) magnetron reactive sputtering. The deposition parameters, such as the substrate temperature and tape moving speed, were systematically investigated. X-ray diffraction analysis confirmed that optimized YSZ/Y2O3buffer layers showed excellent in-plane and out-of-plane textures. Atomic force microscope revealed a smooth, dense and crack-free surface. The subsequent CeO2cap layer and 1μm-thick YBa2Cu3O7-δfilm sequentially prepared, showing the critical current densityJcunder 77K, self-field of 1.4MA/cm2.

scholarly journals The Influence of Surface Morphology of Buffer Layer on the Critical Current Density in YBCO Coated Conductors

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Jie Xiong ◽  
Yudong Xia ◽  
Fei Zhang ◽  
Yan Xue ◽  
Kai Hu ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Critical Current Density ◽  
Buffer Layer ◽  
Critical Current ◽  
Current Density ◽  
Coated Conductors ◽  
Buffer Layers ◽  
X Ray Diffraction ◽  
Ybco Films ◽  
Surface Morphologies

1 μm-thickYBa2Cu3O7-δ(YBCO) films were grown on the Y2O3/yttria stabilized zirconia (YSZ)/CeO2buffer layers with different surface morphologies using direct-current sputtering. The critical current density (Jc) value of YBCO was 1.1 MA/cm2when the root mean square surface roughness (Rrms) of the buffer layer was 2.5 nm. As theRrmsof the buffer layer increased to 15 nm, theJcdecreased to 0.3 MA/cm2. X-ray diffraction and scanning electron microscopy showed the strong relevance of the evolution of the structure and surface morphologies of YBCO films with the buffer layer of differentRrms. A model was proposed to explain the influence of surface morphology on the superconducting properties of YBCO films.

CeO2 Thin Films as Buffer Layers for Si/YBCO Integrated Microelectronics

2003 ◽  
Vol 768 ◽  
Author(s):  
Elena Tresso ◽  
V. Ballarini ◽  
A. Chiodoni ◽  
R. Gerbaldo ◽  
G. Ghigo ◽  
...  
Keyword(s):  
Film Growth ◽  
Ybco Film ◽  
Annealing Treatment ◽  
Lattice Parameter ◽  
Buffer Layers ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Properties Of Superconductors

AbstractThe unique properties of superconductors such as radiation hardness and high microwave performances [1-3] make the integration with semiconductor conventional electronics a stimulating challenge. Many attempts have been tried to obtain good quality YBa2Cu3O7-x (YBCO) films on Si substrates, with the aim of taking advantage from the properties of both materials, but interdiffusion reactions and a poor lattice and thermal expansion coefficient matching require the use of a buffer layer at the semiconductor/superconductor interface. Yttria-stabilized zirconia (YSZ), Y2O3, MgO, SrTiO3, CeO2 and their combinations have been proposed and used as buffer layers in the case of Si/YBCO systems. In this paper we report on annealing treatments performed on Si/CeO2 bilayers. A set of optimized samples with deposition temperatures ranging from 100°C to 800°C has been radiatively heated at two different annealing temperatures, in N2 and O2 atmospheres. All the samples have been characterized by X-ray diffraction, Atomic Force Microscopy, micro-Raman spectroscopy. The preferential grain orientation, the lattice parameter, the crystals dimensions, the surface roughness have been studied. As a preliminary tentative, we report on YBCO film growth on the top of CeO2/Si optimized bi-layer before undergoing annealing treatment. This YBCO film resulted to be a-axis preferential oriented, with some contribution of c-axis oriented grains.

MOD oxide buffer layers on metallic substrates for YBCO coated conductors

2013 ◽  
Vol 1579 ◽  
Author(s):  
A. Augieri ◽  
M.R. Mancini ◽  
A. Vannozzi ◽  
A. A. Angrisani ◽  
F. Fabbri ◽  
...  
Keyword(s):  
Coated Conductors ◽  
Buffer Layers ◽  
Recrystallization Process ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Metallic Substrates ◽  
Force Microscopy ◽  
Atomic Force ◽  
Metal Organic ◽  
Ft Ir

ABSTRACTWe present a detailed study carried out on oxide buffer layers grown by Metal-Organic Decomposition (MOD) on metallic substrates for YBa2Cu3O7-x (YBCO) coated conductor applications. Precursor solutions have been made starting from acetates or pentanedionates and characterized by means of Differential Scanning Calorimetry (DSC) and Thermogravimetric (TG) analyses coupled with Fourier Transform Infra-Red spectroscopy (FT-IR). Thin buffer layers have been grown by spin-coating on Ni-5at.%W substrates. X-ray diffraction spectra (XRD), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) have been employed in order to optimize buffer layers in terms of film microstructure and surface quality, with the final aims of producing a suitable template for YBCO growth. It will be shown that the optimization of the recrystallization process can lead to high quality buffer layer allowing the growth of YBCO films showing good superconductive properties.

scholarly journals Ultrafine metal-polymer catalysts based on polyconjugated systems for Fisher–Tropsch synthesis

2020 ◽  
Vol 92 (6) ◽  
pp. 977-984
Author(s):  
Mayya V. Kulikova ◽  
Albert B. Kulikov ◽  
Alexey E. Kuz’min ◽  
Anton L. Maximov
Keyword(s):  
Tropsch Synthesis ◽  
X Ray Diffraction ◽  
Fischer Tropsch ◽  
Force Microscopy ◽  
Composite Catalysts ◽  
Fe Catalyst ◽  
Atomic Force ◽  
And Function ◽  
Metal Polymer

AbstractFor previously studied Fischer–Tropsch nanosized Fe catalyst slurries, polymer compounds with or without polyconjugating structures are used as precursors to form the catalyst nanomatrix in situ, and several catalytic experiments and X-ray diffraction and atomic force microscopy measurements are performed. The important and different roles of the paraffin molecules in the slurry medium in the formation and function of composite catalysts with the two types of aforementioned polymer matrices are revealed. In the case of the polyconjugated polymers, the alkanes in the medium are “weakly” coordinated with the metal-polymer composites, which does not affect the effectiveness of the polyconjugated polymers. Otherwise, alkane molecules form a “tight” surface layer around the composite particles, which create transport complications for the reagents and products of Fischer-Tropsch synthesis and, in some cases, can change the course of the in situ catalyst formation.

Composition and Structure of Epitaxial CaF2 Layers at the First Stages of Their Growth on Si(111)

2001 ◽  
Vol 696 ◽  
Author(s):  
R. Würz ◽  
W. Bohne ◽  
W. Fuhs ◽  
J. Röhrich ◽  
M. Schmidt ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Film Growth ◽  
Stoichiometric Composition ◽  
Interface Reaction ◽  
Heavy Ion ◽  
Interface Layer ◽  
Buffer Layers ◽  
Ex Situ ◽  
Elastic Recoil ◽  
Detection Analysis

AbstractCaF2 films with thicknesses in the monolayer range (<20 Å) were grown on Si(111) by evaporation from a CaF2 source at UHV conditions. They were characterized ex-situ by Heavy-Ion Elastic Recoil Detection Analysis (HI-ERDA), RBS/Channeling, X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM). The F/Ca ratio of the films was found to depend on the growth temperature Ts and to deviate appreciably from the stoichiometric composition (F/Ca=2). Due to an interface reaction which leads to a CaF-interface layer a change from polycrystalline to epitaxial growth occurs at Ts=450°C. At higher temperature film growth started with a closed layer of CaF on top of which CaF2 layers with an increasing fraction of pinholes were formed. By means of a two-step process at different temperatures, the amount of pinholes could be strongly reduced. It was found, that buffer layers of CaF2 with a CaF interface layer introduced in Au/p-Si contacts enhance the barrier height by as much as 0.36eV to values of 0.64eV.

Growth study of epitaxial FexZn1−xF2 thin films

2001 ◽  
Vol 16 (6) ◽  
pp. 1769-1775 ◽  
Author(s):  
J. McChesney ◽  
M. Hetzer ◽  
H. Shi ◽  
T. Charlton ◽  
D. Lederman
Keyword(s):  
Thin Films ◽  
Film Growth ◽  
Magnetic Phase Diagram ◽  
Epitaxial Thin Films ◽  
X Ray Diffraction ◽  
Growth Study ◽  
Lattice Match ◽  
Different Temperatures ◽  
Bulk Single Crystals ◽  
The Ideal

The FexZn1−xF2 alloy has been shown to be a model system for studying the magnetic phase diagram of dilute magnets. Whereas the growth of bulk single crystals with fixed Zn concentrations is difficult, the thin film growth is comparatively simpler and more flexible. To gain an understanding of the growth of FexZn1−xF2 films, a method was developed to grow smooth films at fixed concentrations. This was done by depositing a MgF2 buffer layer on MgF2(001) substrates and then depositing FeF2 and ZnF2 [001]-orientated epitaxial thin films at different temperatures. Surprisingly, the lattice spacing depends strongly on the growth temperature, for 44-nm-thick FeF2 films and 77-nm-thick ZnF2 films. This indicates a significant amount of stress, despite the close lattice match between the films and the MgF2 substrate. Thick alloy samples (approximately 500 nm thick) were grown by co-evaporation from the FeF2 and ZnF2 sources at the ideal temperature determined from the growth study, and their concentration was accurately determined using x-ray diffraction.

Substrate Temperature and La0.9Sr0.1Ga0.8Mg0.2O3-δ Electrolyte Film Growth by Radio Frequency Magnetron Sputtering

2015 ◽  
Vol 833 ◽  
pp. 127-133
Author(s):  
Jie Yu ◽  
Jie Xing ◽  
Xiu Hua Chen ◽  
Wen Hui Ma ◽  
Rui Li ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Substrate Temperature ◽  
Radio Frequency ◽  
Film Growth ◽  
Rf Magnetron Sputtering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrolyte Film ◽  
Porous Anode

La0.9Sr0.1Ga0.8Mg0.2O3-δ (LSGM) electrolyte thin films were fabricated on La0.7Sr0.3Cr0.5Mn0.5O2.75 (LSCM) porous anode substrates by Radio Frequency (RF) magnetron sputtering method. The compatibility between LSGM and LSCM was examined. Microstructures of LSGM thin films fabricated were observed by scanning electron microscope (SEM). The effect of substrate temperature on LSGM thin films was clarified by X-ray Diffraction (XRD). Deposition rate increases firstly at the range of 50°C~150°C, and then decreases at the range of 150°C ~300°C. After annealing, perovskite structure with the same growth orientation forms at different substrate temperature. Crystallite size decreases at first, to the minimum point at 150°C, then increases as substrate temperature rises.

Combinatorial (Ba,Sr)TiO3 thin film growth: X-ray diffraction and Raman spectroscopy

2009 ◽  
Vol 106 (3) ◽  
pp. 034108 ◽  
Author(s):  
H. Bouyanfif ◽  
J. Wolfman ◽  
M. El Marssi ◽  
Y. Yuzyuk ◽  
R. Bodeux ◽  
...  
Keyword(s):  
Thin Film ◽  
Raman Spectroscopy ◽  
Film Growth ◽  
Thin Film Growth ◽  
Tio3 Thin Film ◽  
X Ray Diffraction ◽  
X Ray

Low Pressure MOCVD Growth and Characterization of GaAs and InP on Silicon Substrates

1988 ◽  
Vol 126 ◽  
Author(s):  
M. Razeghi ◽  
M. Defour ◽  
F. Omnes ◽  
J. Nagle ◽  
P. Maurel ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Low Pressure ◽  
Buffer Layers ◽  
Silicon Substrates ◽  
Misfit Dislocations ◽  
X Ray Diffraction ◽  
High Quality ◽  
Mocvd Growth ◽  
Vapor Deposition Technique ◽  
Low Pressure Mocvd

ABSTRACTHigh quality GaAs and InP have been grown on silicon substrates, using low pressure metalorganic chemical vapor deposition technique. The growth temperature is 550°C and the growth rate 100 A/min.Photoluminescence, X-ray diffraction and electrochemical profiling verified the high quality of these layers. The use of superlattices as buffer layers, (GaAs/GaInP) in the case of GaAs/Si and (GaInAsP/InP) in the case of InP/Si, decreased the amount of misfit dislocations in the epitaxial layer. Carrier concentrations as low as 5.1015 cm−3 have been measured by electrochemical profiling.

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