Investigation of Cation Disorder In ‘C’ Axis Ybco 123 Thin Films Using Raman Microscopy

1995 ◽  
Vol 401 ◽  
Author(s):  
L. F. Cohen ◽  
Y. B. Li ◽  
G. Gibson ◽  
J. MacManus-Driscoll
Keyword(s):  
Thin Films ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Coulometric Titration ◽  
Lattice Parameter ◽  
Raman Microscopy ◽  
Oxygen Stoichiometry ◽  
X Ray ◽  
Cation Disorder ◽  
Different Levels

AbstractTwo 123 thin films grown by e-beam evaporation have been studied using Raman microscopy. The films were grown under different conditions of temperature and oxygen partial pressure and show different levels of cation disorder as determined from the ‘c’ axis lattice parameter in combination with x-ray data. The oxygen stoichiometry in each film was changed by controlled anneals using a coulometric titration apparatus. As a result we report on the sensitivity of the 500cm−1 and 585cm−1 Raman peak to the oxygen stoichiometry and how the intensity and position of these peaks can be used to detect or confirm the presence of a small amount of cation disorder.

Growth and Characterization of ZnO Thin Films Grown by Pulsed Laser Deposition

2011 ◽  
Vol 383-390 ◽  
pp. 6289-6292
Author(s):  
Jian Ting He ◽  
Bo Xue Tan ◽  
Qin Qin Wei ◽  
Yuan Bin Su ◽  
Shu Lian Yang
Keyword(s):  
Thin Films ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Pulsed Laser Deposition ◽  
Photoelectron Spectroscopy ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Zno Thin Films ◽  
X Ray ◽  
Partial Pressures

ZnO thin films were deposited on n-Si (111) substrates at various oxygen partial pressures by pulsed laser deposition (PLD). X-ray diffraction (XRD), scanning electron microscopy (SEM) were used to analyze the influence of the oxygen partial pressure on the crystallization and morphology of the ZnO thin films. An optimal crystallized ZnO thin film was observed at the oxygen partial pressure of 6.5Pa. X-ray photoelectron spectroscopy (XPS) was used to analyze the surface components and distribution status of various elments in ZnO thin films. It was found that ZnO thin films were grown in Zn-rich state.

Effects of Oxygen Partial Pressure on the Properties of SnOx Thin Films Doped with Indium

2021 ◽  
Vol 16 (5) ◽  
pp. 819-826
Author(s):  
Myeong Kyun Lyou ◽  
Hyunki Kim ◽  
SeoGwon Kim ◽  
Byung Seong Bae ◽  
Eui-Jung Yun
Keyword(s):  
Thin Films ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Hall Effect ◽  
Photoelectron Spectroscopy ◽  
Secondary Ion Mass Spectrometry ◽  
Hall Effect Measurement ◽  
Amorphous Structure ◽  
X Ray ◽  
Hall Effect Measurements

This study examined the effects of the oxygen partial pressure on the properties of heavily indium-doped tin-oxide (In-SnOx) thin films grown at room temperature by reactive direct-current pulse sputtering from a mixed metallic target containing Sn (70 atomic %)-In (30 atomic %). X-ray photoelectron spectroscopy (XPS), dynamic secondary-ion mass spectrometry, X-ray diffraction (XRD), and Hall Effect measurements showed that the In-SnOx samples prepared with oxygen pressures of 10–20% had metallic properties. This was attributed to the notable Sn0 area ranges of 5.6–17.3%, low resistivity ranges of 5.5×10−3–2×10−4 Ωcm, and the high carrier concentration ranges of 3.5×1021–5.1×1022/cm3. On the other hand, the Sn4+ area and the resistivity increased significantly to 73.3% and 9.4 Ωcm. In comparison, the Sn2+ area and the electron concentration decreased dramatically to 23.6% and 6.5×1016/cm3, respectively, with increasing oxygen partial pressure up to 30%. The samples prepared with oxygen pressures higher than 20% exhibited nonmetallic properties with the dominant n-type SnO2 phase. This steep increase in the Sn4+ area was attributed to an increase in the oxygen contents in the samples, resulting in a decrease in the number of oxygen vacancy donors in the samples prepared with oxygen pressures higher than 20%. The decrease in the Sn2+ area was related to a decrease in the indium (In) contents in the samples, which also decreased the number of metal acceptors in the samples. XRD also showed that the metallic indium stannide (In0.2Sn0.8) and In–Sn–O(ITO) peaks coexisted for samples prepared with an oxygen pressure of 0–10%. In contrast, the samples prepared with oxygen pressures higher than 20% had an amorphous structure with SnO2 and SnO phases, supporting the XPS and Hall Effect measurement results.

Intrinsic Paramagnetic Defects in Zirconium and Hafnium Oxide Films

2012 ◽  
Vol 1394 ◽  
Author(s):  
Robert N. Schwartz ◽  
Heinrich G. Muller ◽  
Paul M. Adams ◽  
James D. Barrie ◽  
Ronald C. Lacoe
Keyword(s):  
Thin Films ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Hafnium Oxide ◽  
Theoretical Work ◽  
Fused Silica ◽  
Preferred Orientation ◽  
Oxygen Stoichiometry ◽  
Pole Figures ◽  
Oxygen Hole

ABSTRACTThin films of zirconium oxide (ZrOx) and hafnium oxide (HfOx) were rf sputtered onto fused silica substrates in an oxygen rich argon environment. Pure zirconium and hafnium targets were used, and the oxygen partial pressure was varied to control the oxygen stoichiometry. Measurement of the EPR characteristics of the ZrOx films indicated two peaks corresponding to two orientations of the magnetic field. This anisotropic response suggested the films were polycrystalline with a preferred orientation. This was confirmed by XRD pole figures. The measured g-values for the ZrOx films were less than the free-spin g-value, indicating the defects corresponded to electron traps. It was further shown that the lower the oxygen partial pressure during deposition, the larger the EPR response, strongly suggesting the traps correspond to oxygen vacancies in ZrOx. Hafnium oxide thin films were also characterized by EPR. The EPR measurements indicated the presence of a single resonance peak, suggesting these films were polycrystalline without a preferred orientation or amorphous. XRD measurements confirmed that the HfOx films were amorphous. The g-value for these films was greater than that the free-spin value, indicating the presence of possibly self-trapped oxygen hole centers. These results will be discussed in the context of prior experimental and theoretical work on these systems.

Inhomogeneity and Microstructure in e-Beam Evaporated ZrO2 Films

1990 ◽  
Vol 208 ◽  
Author(s):  
M. Bellotto ◽  
C. Cremnonesi ◽  
F. Parmigiani ◽  
M. Scagliotti ◽  
S. Beretta
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Oxygen Partial Pressure ◽  
Zirconium Dioxide ◽  
Oxygen Stoichiometry ◽  
Composition Gradient ◽  
X Ray Diffraction ◽  
X Ray ◽  
Partial Pressures ◽  
Microstructure Of The Material

ABSTRACTThin films of zirconium dioxide are deposited by e-beam evaporation on optically polished borosilicate crown glass. Two different oxygen partial pressures in the chamber are used. The optical properties of the films are characterized by ellipsometry. The influence of oxygen stoichiometry on the composition and microstructure of the material is investigated by polycrystalline X-ray diffraction for different film thicknesses. The films are found to be inhomogeneous, and a composition gradient (i.e. amorphous ⇔ tetragonal ⇔ monoclinic) is observed from the substrate to the surface. The oxygen partial pressure influences the growth of the films.

In-situ analysis of chemical expansion and stability of SOFC cathodes

2014 ◽  
Vol 1655 ◽  
Author(s):  
Mirela Dragan ◽  
Scott Misture
Keyword(s):  
High Temperature ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Lattice Parameter ◽  
Low Oxygen ◽  
X Ray Diffraction ◽  
Chemical Expansion ◽  
X Ray ◽  
Reducing Conditions ◽  
The Stability

ABSTRACTIn this work high-temperature X-ray diffraction has been used to investigate thermal and chemical expansion as well as overall phase stability for various cathode materials: Ba0.5Sr0.5Co0.8Fe0.2O3 (BSCF), La0.3Sr0.7CoO3 (LSC37), La0.6Sr0.4CoO3 (LSC64) and La0.6Sr0.4Fe0.8Co0.2O3 (LSCF), as a function of temperature in reducing conditions. When perovskites materials are under a low oxygen partial-pressure condition, the lattice parameter and overall dimension increase. Their chemical expansion has comparable values. From the viewpoint of the stability of these phases, the high-temperature X-ray diffraction results indicate no phase decomposition can be one of the reasons for material failure at the current experimental oxygen partial pressure. LSF is most stable, while LSC and LSCF form oxygen vacancy-ordered phases and then decompose when heated to 1000°C under atmospheres with pO2 as low as 10-5 atm.

Some Aspects of the Nonstoichiometric and Thermodynamic Behavior of the YBa2Cu3Oz System

1989 ◽  
Vol 156 ◽  
Author(s):  
M. Tetenbaum ◽  
L. Curtiss ◽  
B. Czech ◽  
B. Tani ◽  
M. Blander
Keyword(s):  
Low Temperature ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Coulometric Titration ◽  
Temperature Data ◽  
Oxygen Stoichiometry ◽  
Miscibility Gap ◽  
Thermodynamic Behavior ◽  
Partial Pressures ◽  
Titration Technique

ABSTRACTThe nonstoichiometric and thermodynamic behavior of the YBa2Cu3Ox system as a function of oxygen partial pressure and temperature is being investigated by means of a coulometric titration technique. The oxygen content of the superconductor can be varied coulometrically by well-defined small amounts and the equilibrium partial pressures determined from the EMF. The oxygen stoichiometry in YBa2Cu3Ox as a function of oxygen partial pressure shows a change of curvature around x = 6.55–6.75 and an inflection around x ≅ 6.65 at temperatures between 400–500°C. These new low temperature data are consistent with the presence of a miscibility gap at lower temperatures, which is similar to that postulated in several theoretical papers.

scholarly journals Tunable Optical Properties of Amorphous-Like Ga2O3 Thin Films Deposited by Electron-Beam Evaporation with Varying Oxygen Partial Pressures

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1760
Author(s):  
Shijie Li ◽  
Chen Yang ◽  
Jin Zhang ◽  
Linpeng Dong ◽  
Changlong Cai ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Electron Beam ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Photoelectron Spectroscopy ◽  
Test System ◽  
Electron Beam Evaporation ◽  
X Ray ◽  
Ga2o3 Film

Ga2O3 thin films were fabricated by the electron-beam evaporation technique at a varying oxygen partial pressure from 0 to 2.0 × 10−2 Pa. The effect of oxygen partial pressure on the crystalline structure and optical properties of the Ga2O3 films was analyzed using sophisticated techniques including X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Raman spectroscopy, spectroscopic ellipsometry, ultraviolet-visible spectroscopy and a laser-induced damage test system. The correlation between the oxygen partial pressure and the film’s properties in optics and materials were investigated. XRD and Raman revealed that all films were amorphous in spite of applying a varying oxygen partial pressure. With the change of oxygen partial pressure, XPS data indicated that the content of oxygen in the Ga2O3 films could be broadly modulable. As a result, a changeable refractive index of the Ga2O3 film is realizable and a variable blue-shift of absorption edges in transmittance spectra of the films is achievable. Moreover, the damage threshold value varied from 0.41 to 7.51 J/cm2 according to the rise of oxygen partial pressure. These results demonstrated that the optical properties of Ga2O3 film can be broadly tunable by controlling the oxygen content in the film.

Growth and Characterization of PbTiO3 and Pb(Zr,Ti)O3 Thin Films by MOCVD

1994 ◽  
Vol 361 ◽  
Author(s):  
Y. Gao ◽  
W. Dong ◽  
B.A. Turtle
Keyword(s):  
Thin Films ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Depth Profiling ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Pzt Films ◽  
Uniform Composition

ABSTRACTFerroelectric PbTiO3 and Pb(Zr,Ti)O3 thin films with a perovskite structure were grown on MgO and Pt/Ti/SiO2/Si by MOCV.D. The microstructure and composition of the films were characterized by x-ray diffraction, SEM, and AES. Preferred orientation of either (111) or (100)/(001) was obtained on the Pt/Ti/SiO2/Si substrates at temperatures from 600 °C to 650 °C The preferred (111) orientation was attributed to the formation of the Pt3Ti phase in the Pt layer of the substrates, whereas the (100)/(001) orientations were inferred as the growth rate effect. AES depth profiling indicated a uniform composition through the thickness of the PZT films. However, SEM showed different topography and microstructure of the PZT films deposited in different oxygen partial pressure. Electrical properties of the PZT films appear varied as a function of the oxygen partial pressure in the reactor.

XPS Analysis of ZnO Thin Films Obtained by Pulsed Laser Deposition

2011 ◽  
Vol 383-390 ◽  
pp. 6293-6296 ◽  
Author(s):  
Jian Ting He ◽  
Bo Xue Tan ◽  
Yuan Bin Su ◽  
Shu Lian Yang ◽  
Qin Qin Wei
Keyword(s):  
Thin Films ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Pulsed Laser Deposition ◽  
Photoelectron Spectroscopy ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Zno Thin Films ◽  
X Ray ◽  
Partial Pressures

Highly c-axis oriented ZnO thin films were deposited on n-Si (111) substrate at various oxygen partial pressures by pulsed laser deposition (PLD). X-ray diffraction (XRD), Atomic force microscopy (AFM) were used to analyze the influence of the oxygen partial pressure on the crystallization and morphology of the ZnO thin films. X-ray photoelectron spectroscopy (XPS) was used to analyze relationships between chemical shifts of XPS energy spectra and stoichiometric ratios of ZnO thin films, and quantitative relationships between content of Zn, O and oxygen partial pressures. An optimal crystallized and stoichiometric ZnO thin film was observed at the oxygen partial pressure of 6.5Pa.

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