Chemical Control of Stress in Sol-Gel Derived Titania Films and Their Pressure Dependent Optical Properties

ABSTRACTOptical properties and durability of thin films are influenced by strain which can be evaluated from frequency shifts of the lattice phonon lines in measured Raman spectra. The response of titania samples to applied pressure is reported in this work. Anatase and rutile samples of thin films (sol-gel and sputter deposited) and bulk materials have been subjected to hydrostatic pressures approaching 100 kbar in a diamond anvil cell. Results indicate that the rutile samples exhibit similar responses to applied pressure. Anatase sol-gel films exhibit a pressure-dependent response that suggests that the sol-gel film is more compressible than the bulk material, and a pressure-induced phase transformation observed for the bulk material is inhibited in the anatase sol-gel film. The anomalous pressure response of the anatase sol-gel film may result from the film microstructure which has been shown by transmission electron microscopy to consist of spheres of crystalline TiO2 surrounded by microscopic voids.

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Microstructure and Optical Properties of Co Sputter Deposited Si-Al Nanocomposite Thin Films

MRS Proceedings ◽

10.1557/proc-648-p3.47 ◽

2000 ◽

Vol 648 ◽

Author(s):

F. Niu ◽

P.J. Dobson ◽

B. Cantor

Keyword(s):

Thin Films ◽

Optical Properties ◽

Optical Absorption ◽

Absorption Peak ◽

Al Content ◽

Al Nanoparticles ◽

Transmission Electron ◽

Effective Medium Theories ◽

Nanocomposite Thin Films ◽

Sputter Deposited

AbstractNovel Si-Al nanocomposite thin films were made by radio frequency co-sputtering of Si and Al with Al content from 0 at.% to 69 at.%. Microstructure and optical properties of the films were characterised by conventional and high resolution transmission electron microscopyand spectrometry in the wavelength range from 200 to 3000 nm. The film microstructure consisted of Al nanoparticles (2-9 nm) embedded in an amorphous Si-Al matrix. Optical absorption spectra of the films up to 50 at.% Al exhibited a sharp absorption peak below500 nm and relatively low absorption above 500 nm. In addition, the absorption peak shifted towards longer wavelengths and the general absorption above 500 nm increased remarkably as Al content increased. For the Si-69at.%Al films, however, an absorption plateau appeared between 300 nm to 700 nm and a second weak and broad absorption peak appeared at around 900 nm. The results are analysed and compared with the optical absorption predicted by various effective medium theories.

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Synthesis and Interface Structure of Sol Gel YBa2Cu3Ox Thin Films for Conductor Development

MRS Proceedings ◽

10.1557/proc-659-ii6.4 ◽

2000 ◽

Vol 659 ◽

Author(s):

Donglu Shi ◽

Yongli Xu ◽

S. X. Wang ◽

L. M. Wang ◽

Shaun M. McClellan

Keyword(s):

Thin Films ◽

Sol Gel ◽

X Ray Diffraction ◽

Silver Alloy ◽

Ybco Thin Films ◽

Transmission Electron ◽

Gel Film ◽

Peritectic Solidification ◽

Sol Gel Synthesis

ABSTRACTIn our previous work we have obtained YBCO thick films on silver alloy substrate via the peritectic solidification. To further develop grain-textured YBCO thin films for conductor development, in this study, we have used a sol gel approach to deposit YBCO thin films on two different substrates, namely, yttrium-stabilized zirconia (YSZ) and a silver alloy containing 10 % of palladium (Ag –10%Pd). We have found that the sol gel film on YSZ exhibits an epitaxial growth. This is confirmed by both x-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). XRD data also indicate that the YBCO film on Ag-10%Pd has a c-axis grain orientation. The details are reported on sol gel synthesis and XRD and HRTEM characterization of the YBCO thin films.

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Characterization of reactive phase formation in sputter-deposited Ni/Al multilayer thin films using TEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100167469 ◽

1996 ◽

Vol 54 ◽

pp. 1000-1001

Author(s):

G. Lucadamo ◽

K. Barmak ◽

C. Michaelsen

Keyword(s):

Thin Films ◽

Phase Formation ◽

Dark Field ◽

Nickel Layer ◽

Multilayer Thin Films ◽

Cross Sectional ◽

Dark Field Imaging ◽

Transmission Electron ◽

Sputter Deposited ◽

Constant Heating

The subject of reactive phase formation in multilayer thin films of varying periodicity has stimulated much research over the past few years. Recent studies have sought to understand the reactions that occur during the annealing of Ni/Al multilayers. Dark field imaging from transmission electron microscopy (TEM) studies in conjunction with in situ x-ray diffraction measurements, and calorimetry experiments (isothermal and constant heating rate), have yielded new insights into the sequence of phases that occur during annealing and the evolution of their microstructure.In this paper we report on reactive phase formation in sputter-deposited lNi:3Al multilayer thin films with a periodicity A (the combined thickness of an aluminum and nickel layer) from 2.5 to 320 nm. A cross-sectional TEM micrograph of an as-deposited film with a periodicity of 10 nm is shown in figure 1. This image shows diffraction contrast from the Ni grains and occasionally from the Al grains in their respective layers.

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STRUCTURAL, OPTICAL PROPERTIES AND PHOTOCATALYTIC ACTIVITY OF NANOCRYSTALLINE TiO2 THIN FILMS DEPOSITED BY SOL-GEL SPIN COATING

i-manager s Journal on Material Science ◽

10.26634/jms.7.1.15719 ◽

2019 ◽

Vol 7 (1) ◽

pp. 28

Author(s):

KOMARAIAH DURGAM ◽

RADHA EPPA ◽

REDDY M. V. RAMANA ◽

KUMAR J. SIVA ◽

R. SAYANNA ◽

...

Keyword(s):

Thin Films ◽

Optical Properties ◽

Photocatalytic Activity ◽

Spin Coating ◽

Sol Gel ◽

Tio2 Thin Films ◽

Nanocrystalline Tio2

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Sol-gel growth of Ni doped CdS on glass substrates: effect of spin coating speed and dopant concentration

Nanoscience &Nanotechnology-Asia ◽

10.2174/2210681210999200423120817 ◽

2020 ◽

Vol 10 ◽

Author(s):

Atefeh Nazari Setayesh ◽

Hassan Sedghi

Keyword(s):

Thin Films ◽

Optical Properties ◽

Spin Coating ◽

Optical Band Gap ◽

Dopant Concentration ◽

Rotation Speed ◽

Sol Gel ◽

Band Gap Energy ◽

Gap Energy ◽

Glass Substrates

Background: In this work, CdS thin films were synthesized by sol-gel method (spin coating technique) on glass substrates to investigate the optical behavior of the film. Methods: Different substrate spin coating speeds of 2400, 3000, 3600 rpm and different Ni dopant concentrations of 0 wt.%, 2.5 wt.%, 5 wt.%) were investigated. The optical properties of thin films such as refraction index, extinction coefficient, dielectric constant and optical band gap energy of the layers were discussed using spectroscopic ellipsometry method in the wavelength range of 300 to 900 nm. Results: It can be deduced that substrate rotation speed and dopant concentration has influenced the optical properties of thin films. By decreasing rotation speed of the substrate which results in films with more thicknesses, more optical interferences were appeared in the results. Conclusion: The samples doped with Ni comparing to pure ones have had more optical band gap energy.

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Sol-gel synthesis of textured lanthanum titanate thin films

Journal of Materials Research ◽

10.1557/jmr.2003.0046 ◽

2003 ◽

Vol 18 (2) ◽

pp. 357-362 ◽

Cited By ~ 12

Author(s):

Mary M. Sandstrom ◽

Paul Fuierer

Keyword(s):

Thin Films ◽

Sol Gel ◽

Precursor Solution ◽

Solution Concentration ◽

Optical Measurements ◽

Layered Perovskite ◽

Orientation Factor ◽

Anisotropic Structures ◽

Sol Gel Films ◽

Sol Gel Synthesis

Control over crystallographic orientation in thin films is important, particularly with highly anisotropic structures. Because of its ferroelectric nature, the layered perovskite La2Ti2O7 has interesting piezoelectric and electrooptic properties that may be exploited when films are highly textured. Sol-gel films with an orientation factor of greater than 95% were fabricated without relying on epitaxial (lattice-matching) growth from the substrate. Film orientation and crystallization were confirmed by x-ray diffraction, scanning electron microscopy, atomic force microscopy, and optical measurements. The particle sizes in all precursor solutions were measured by dynamic light scattering experiments. Experimental results indicate that film orientation is a function of precursor solution concentration, size of the molecular clusters in the solution, and film thickness.

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