Dislocation Defect Layer-Induced Magnetic Bi-states Phenomenon in Epitaxial La0.7Sr0.3MnO3(111) Thin Films

2021 ◽  
Author(s):  
Yanan Zhao ◽  
Yaojin Li ◽  
Chen Chen ◽  
Guohua Dong ◽  
Shukai Zhu ◽  
...  
Keyword(s):  
Thin Films ◽  
Defect Layer ◽  
Dislocation Defect

TiO2/ZnO PHOTONIC CRYSTAL PREPARED BY SPRAY PYROLYSIS METHOD: APPLICATION TO MULTICHANNEL FILTER

2019 ◽  
Vol 27 (07) ◽  
pp. 1950181
Author(s):  
F. KANOUNI ◽  
S. AMARA ◽  
A. ASSALI ◽  
F. ARAB ◽  
Q. ZOU
Keyword(s):  
Thin Films ◽  
Photonic Crystal ◽  
Spray Deposition ◽  
Single Layer ◽  
Diffraction Method ◽  
Optical Transmittance ◽  
Defect Layer ◽  
Spray Pyrolysis Method ◽  
Titanium Chloride ◽  
Multichannel Filter

Single-layer titanium dioxide (TiO2, ZnO, double-layer TiO2/ZnO and multilayer TiO2/ZnO/TiO2/ZnO were grown on ordinary glass substrate by ultrasonic spray deposition at 300∘C. Titanium chloride, zinc acetate and deionized water were employed as precursors. The ultraviolet–visible spectrometer spectra show that the quality of optical transmittance in visible wavelength range decreases as the number of bilayers increases. The crystalline phase of the thin films was identified through X-ray diffraction method with diffraction patterns scan used at 2[Formula: see text] from 10∘ to 90∘. From the DRX results, it is found that the crystallinity is enhanced when the number of TiO2/ZnO layers increased. From the 2D/3D atomic force microscopy (AFM) analysis, it is found that the surface of the films was covered by triangle-like particles. However, bilayer and multilayer TiO2/ZnO thin films show smooth and compacted surface roughnesses compared to single-layer TiO2 and ZnO, respectively. In addition to this experimental work, a multichannel filter based on TiO2/ZnO subphotonic crystals is suggested. The transmission properties of this filter have been investigated by means of the transfer-matrix method (TMM). The idea is to import a wedge of air with an apex angle as the defect layer to disturb the original periodicity of the oxide photonic crystal and generate some new kind of multichannel filtering properties.

Structural studies on Tl–Ca–Ba–Cu−0 superconducting thin films

1993 ◽  
Vol 8 (4) ◽  
pp. 720-726 ◽  
Author(s):  
Bruno Morosin ◽  
Grant M. Norton ◽  
Barry C. Carter ◽  
E.L. Venturini ◽  
D.S. Ginley
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Profile Analysis ◽  
Defect Layer ◽  
Line Profile Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lattice Fringe ◽  
Transmission Electron ◽  
Good Agreement

The microstructure of mixed phase, c-axis oriented Tl–Ca–Ba–Cu–O thin films, exhibiting excellent superconducting properties, has been examined by transmission electron microscopy and x-ray diffraction. Although the stoichiometry of the as-deposited films corresponds to the Tl2Ca2Ba2Cu3O10 phase (Tl-2223, c = 3.6 nm), x-ray diffraction showed these films contain up to 50% of the Tl2CaBa2Cu2O8 phase (Tl-2122, c ≍ 2.9 nm). The x-ray diffraction peaks of the 3.6 nm phase are noticeably broader than those of the 2.9 nm phase, suggesting a smaller coherent size along the c-axis for the 3.6 nm phase Lattice-fringe images of the 2.9 nm phase typically show only an occasional or no defect layer; however, such layer defects are more abundant in the 3.6 nm phase and, though random, occur with sufficiently wide separation and regularity to be consistent with an average coherency of ∼40 nm. The coherent sizes along the c-axis, as determined by x-ray line profile analysis, were 140 nm and 40 nm, respectively, for the 2.9 nm and 3.6 nm phases, in good agreement with those determined by electron microscopy. The estimated width of the layer defects observed in the lattice-fringe images is suggestive, for the most part, of the four Cu-layered phases (Tl-1324 or Tl-2324) and to a lesser degree the two Cu-layered phases (Tl-1122 or Tl-2122).

The study of interfacial reactions of nickel thin films on GaAs

1983 ◽  
Vol 41 ◽  
pp. 156-157
Author(s):  
L.J. Chen ◽  
Y.F. Hsieh
Keyword(s):  
Thin Films ◽  
Integrated Circuits ◽  
Interfacial Reactions ◽  
Metal Contacts ◽  
Nickel Thin Films ◽  
Thin Foils ◽  
The Status ◽  
Si Doped ◽  
Electron Microscopes

One measure of the maturity of a device technology is the ease and reliability of applying contact metallurgy. Compared to metal contact of silicon, the status of GaAs metallization is still at its primitive stage. With the advent of GaAs MESFET and integrated circuits, very stringent requirements were placed on their metal contacts. During the past few years, extensive researches have been conducted in the area of Au-Ge-Ni in order to lower contact resistances and improve uniformity. In this paper, we report the results of TEM study of interfacial reactions between Ni and GaAs as part of the attempt to understand the role of nickel in Au-Ge-Ni contact of GaAs.N-type, Si-doped, (001) oriented GaAs wafers, 15 mil in thickness, were grown by gradient-freeze method. Nickel thin films, 300Å in thickness, were e-gun deposited on GaAs wafers. The samples were then annealed in dry N2 in a 3-zone diffusion furnace at temperatures 200°C - 600°C for 5-180 minutes. Thin foils for TEM examinations were prepared by chemical polishing from the GaA.s side. TEM investigations were performed with JE0L- 100B and JE0L-200CX electron microscopes.

Studies on Water in the Hydration Chamber of a Modified Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 544-545
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Microscope ◽  
Steady State ◽  
Room Temperature ◽  
Small Mass ◽  
Equilibrium Pressure ◽  
Biological Objects ◽  
Mechanical Pump ◽  
Differential Pumping

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

Nucleation and Early Growth of Sputtered thin Films

1970 ◽  
Vol 28 ◽  
pp. 516-517
Author(s):  
Dudley M. Sherman ◽  
Thos. E. Hutchinson
Keyword(s):  
Thin Films ◽  
Electron Beam ◽  
Ion Beam ◽  
Ion Source ◽  
Water Cooling ◽  
Stages Of Growth ◽  
Lens Assembly ◽  
Microscope Technique ◽  
Ion Beam Sputter Deposition

The in situ electron microscope technique has been shown to be a powerful method for investigating the nucleation and growth of thin films formed by vacuum vapor deposition. The nucleation and early stages of growth of metal deposits formed by ion beam sputter-deposition are now being studied by the in situ technique.A duoplasmatron ion source and lens assembly has been attached to one side of the universal chamber of an RCA EMU-4 microscope and a sputtering target inserted into the chamber from the opposite side. The material to be deposited, in disc form, is bonded to the end of an electrically isolated copper rod that has provisions for target water cooling. The ion beam is normal to the microscope electron beam and the target is placed adjacent to the electron beam above the specimen hot stage, as shown in Figure 1.

Macromolecular structures of biological specimens are not obscured by controlled osmium impregnation

1983 ◽  
Vol 41 ◽  
pp. 606-607
Author(s):  
Klaus-Ruediger Peters ◽  
Samuel A. Green
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Critical Point ◽  
Metal Films ◽  
High Magnification ◽  
Osmium Impregnation ◽  
Instrumental Resolution ◽  
20 Nm ◽  
Continuous Metal

High magnification imaging of macromolecules on metal coated biological specimens is limited only by wet preparation procedures since recently obtained instrumental resolution allows visualization of topographic structures as smal l as 1-2 nm. Details of such dimensions may be visualized if continuous metal films with a thickness of 2 nm or less are applied. Such thin films give sufficient contrast in TEM as well as in SEM (SE-I image mode). The requisite increase in electrical conductivity for SEM of biological specimens is achieved through the use of ligand mediated wet osmiuum impregnation of the specimen before critical point (CP) drying. A commonly used ligand is thiocarbohvdrazide (TCH), first introduced to TEM for en block staining of lipids and glvcomacromolecules with osmium black. Now TCH is also used for SEM. However, after ligand mediated osinification nonspecific osmium black precipitates were often found obscuring surface details with large diffuse aggregates or with dense particular deposits, 2-20 nm in size. Thus, only low magnification work was considered possible after TCH appl ication.

The Precipitation of Si in AlCuSi Thin Films

1973 ◽  
Vol 31 ◽  
pp. 34-35 ◽  
Author(s):  
R. M. Anderson
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Heat Treatment ◽  
Solid Solution ◽  
Integrated Circuit ◽  
Copper Film ◽  
Solution Concentration ◽  
X Ray ◽  
Silicon Thin Films ◽  
Before And After

Aluminum-copper-silicon thin films have been considered as an interconnection metallurgy for integrated circuit applications. Various schemes have been proposed to incorporate small percent-ages of silicon into films that typically contain two to five percent copper. We undertook a study of the total effect of silicon on the aluminum copper film as revealed by transmission electron microscopy, scanning electron microscopy, x-ray diffraction and ion microprobe techniques as a function of the various deposition methods.X-ray investigations noted a change in solid solution concentration as a function of Si content before and after heat-treatment. The amount of solid solution in the Al increased with heat-treatment for films with ≥2% silicon and decreased for films <2% silicon.

A standard for transmission electron spectroscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 530-531 ◽  
Author(s):  
Dennis Maher ◽  
David Joy ◽  
Peggy Mochel
Keyword(s):  
Thin Films ◽  
Electron Spectroscopy ◽  
Host Lattice ◽  
Single Element ◽  
Multicomponent Systems ◽  
Transmission Electron ◽  
Major Interest ◽  
Standard Specimens ◽  
Forms Of Carbon ◽  
Electron Energy Loss

A variety of standard specimens is needed in order to systematically investigate the instrumentation, specimen, data reduction and quantitation variables in electron energy-loss spectroscopy (EELS). Pure single element specimens (e.g. various forms of carbon) have received considerable attention to date but certain elements of interest cannot be prepared directly as thin films. Since studies of the first and second row elements in two- or multicomponent systems will be of considerable importance in microanalysis using EELS, there is a need for convenient standards containing these species. For many investigations a standard should contain the desired element, or elements, homogeneously dispersed through a suitable matrix and at an accurately known concentration. These conditions may be met by the technique of implantation.Silicon was chosen as the host lattice since its principal ionization energies, EL23 = 98 eV and Ek = 1843 eV, are well removed from the K-edges of most elements of major interest such as boron (Ek = 188 eV), carbon (Ek = 283 eV), nitrogen (Ek = 400 eV) and oxygen (Ek = 532 eV).

Transmission Electron Microscopy studies of the vacancy ordering in YSI2-X thin films

1991 ◽  
Vol 49 ◽  
pp. 562-563
Author(s):  
F.-R. Chen ◽  
T. L. Lee ◽  
L. J. Chen
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Thin Films ◽  
Diffraction Pattern ◽  
Annealing Temperature ◽  
Lattice Mismatch ◽  
Si Substrate ◽  
Metal Thin Films ◽  
Transmission Electron ◽  
Vacancy Ordering

YSi2-x thin films were grown by depositing the yttrium metal thin films on (111)Si substrate followed by a rapid thermal annealing (RTA) at 450 to 1100°C. The x value of the YSi2-x films ranges from 0 to 0.3. The (0001) plane of the YSi2-x films have an ideal zero lattice mismatch relative to (111)Si surface lattice. The YSi2 has the hexagonal AlB2 crystal structure. The orientation relationship with Si was determined from the diffraction pattern shown in figure 1(a) to be and . The diffraction pattern in figure 1(a) was taken from a specimen annealed at 500°C for 15 second. As the annealing temperature was increased to 600°C, superlattice diffraction spots appear at position as seen in figure 1(b) which may be due to vacancy ordering in the YSi2-x films. The ordered vacancies in YSi2-x form a mesh in Si plane suggested by a LEED experiment.

Analysis of electroless nickel thin films

1991 ◽  
Vol 49 ◽  
pp. 510-511 ◽  
Author(s):  
C. W. Price ◽  
E. F. Lindsey
Keyword(s):  
Thin Films ◽  
Inertial Confinement Fusion ◽  
Electroless Nickel ◽  
Inertial Confinement ◽  
Plating Bath ◽  
X Ray ◽  
Nickel Thin Films ◽  
Nickel Deposits ◽  
Confinement Fusion ◽  
Thickness Measurements

Thickness measurements of thin films are performed by both energy-dispersive x-ray spectroscopy (EDS) and x-ray fluorescence (XRF). XRF can measure thicker films than EDS, and XRF measurements also have somewhat greater precision than EDS measurements. However, small components with curved or irregular shapes that are used for various applications in the the Inertial Confinement Fusion program at LLNL present geometrical problems that are not conducive to XRF analyses but may have only a minimal effect on EDS analyses. This work describes the development of an EDS technique to measure the thickness of electroless nickel deposits on gold substrates. Although elaborate correction techniques have been developed for thin-film measurements by x-ray analysis, the thickness of electroless nickel films can be dependent on the plating bath used. Therefore, standard calibration curves were established by correlating EDS data with thickness measurements that were obtained by contact profilometry.

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