Determination of growth regimes of Pd nanostructures on c-plane sapphire by the control of deposition amount at different annealing temperatures

2017 ◽  
Vol 19 (23) ◽  
pp. 15084-15097 ◽  
Author(s):  
Sundar Kunwar ◽  
Mao Sui ◽  
Puran Pandey ◽  
Quanzhen Zhang ◽  
Ming-Yu Li ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Solid State ◽  
Structural Evolution ◽  
Pd Nanoparticles ◽  
Annealing Temperatures ◽  
Deposition Amount ◽  
Sputter Deposited ◽  
Different Thickness

Semi-spherical and irregular Pd nanoparticles and voids are fabricated on sapphire(0001) by the solid-state dewetting of sputter-deposited Pd thin films at different thickness and temperature. The structural evolution, surface morphology transformation and optical properties of Pd nanostructures are probed.

TEM studies of solid-state reactions in sputter-deposited Nb/Al multilayer thin films

1996 ◽  
Vol 54 ◽  
pp. 1020-1021
Author(s):  
F. Ma ◽  
S. Vivekanand ◽  
K. Barmak ◽  
C. Michaelsen
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Stoichiometric Composition ◽  
Analytical Electron Microscopy ◽  
Grain Structure ◽  
Solid State Reactions ◽  
Multilayer Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sputter Deposited

Solid state reactions in sputter-deposited Nb/Al multilayer thin films have been studied by transmission and analytical electron microscopy (TEM/AEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The Nb/Al multilayer thin films for TEM studies were sputter-deposited on (1102)sapphire substrates. The periodicity of the films is in the range 10-500 nm. The overall composition of the films are 1/3, 2/1, and 3/1 Nb/Al, corresponding to the stoichiometric composition of the three intermetallic phases in this system.Figure 1 is a TEM micrograph of an as-deposited film with periodicity A = dA1 + dNb = 72 nm, where d's are layer thicknesses. The polycrystalline nature of the Al and Nb layers with their columnar grain structure is evident in the figure. Both Nb and Al layers exhibit crystallographic texture, with the electron diffraction pattern for this film showing stronger diffraction spots in the direction normal to the multilayer. The X-ray diffraction patterns of all films are dominated by the Al(l 11) and Nb(l 10) peaks and show a merging of these two peaks with decreasing periodicity.

Preparation and Properties of Niobate Thin Films from Nanosheets

2010 ◽  
Vol 177 ◽  
pp. 201-203
Author(s):  
Jing Chu ◽  
Yu Lin Li ◽  
Bing Xu ◽  
Na Zhang ◽  
Qiang Li
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Phase Structure ◽  
Niobium Oxide ◽  
Oxide Thin Films ◽  
Transmittance Spectra ◽  
Different Thickness ◽  
Soaking Temperature

Niobium oxide thin films were successfully synthesized starting from niobate nanosheets. The microstructure of as-prepared nanosheets was observed by TEM. The morphology of niobate thin films was investigated by SEM. The phase structure was determined by XRD. The transmittance spectra of as-obtained niobium oxide thin films were measured, and the optical properties were studied. The influences of different thickness on optical properties were also analyzed. As-prepared niobium thin films were treated by being heated at different temperature. The effects of soaking temperature on the structure and optical properties of niobium oxide thin films were discussed in detail.

Thickness Dependent Structural and Optical Properties of Cadmium Selenide Thin Films

2013 ◽  
Vol 665 ◽  
pp. 159-167
Author(s):  
M.S. Jani ◽  
H.S. Patel ◽  
J.R. Rathod ◽  
K.D. Patel ◽  
V.M. Pathak ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Hexagonal Wurtzite Structure ◽  
Optical Bandgap ◽  
Bandgap Energy ◽  
Structural And Optical Properties ◽  
Structural Investigations ◽  
Glass Substrates ◽  
Optical Bandgap Energy ◽  
Different Thickness

In this paper structural and optical properties of CdSe thin films with different thickness deposited by thermal evaporation under vacuum onto glass substrates are presented. The structural investigations performed by means of XRD technique showed that the films have a polycrystalline and hexagonal (würtzite) structure. The values of some important parameters of the studied films (absorption coefficient and optical bandgap energy) are determined from transmission spectra. The values of the optical bandgap energy (Eg) calculated from the absorption spectra, ranged between 1.67 - 1.74 eV.

The optical properties of Ag/ZnO nanocomposite thin films with different thickness

Optik ◽  
2017 ◽  
Vol 147 ◽  
pp. 6-13 ◽  
Author(s):  
Linhua Xu ◽  
Gaige Zheng ◽  
Yuzhu Liu ◽  
Jing Su ◽  
Wenjian Kuang ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Nanocomposite Thin Films ◽  
Different Thickness

scholarly journals Preparation and Studying the Optical Properties of (Sb2o3) Thin Films

2018 ◽  
Vol 26 (10) ◽  
pp. 249-256
Author(s):  
Waleed Khalid Kadhim
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Refractive Index ◽  
Optical Properties ◽  
Absorption Coefficient ◽  
Thermal Evaporation ◽  
Glass Slide ◽  
Antimony Trioxide ◽  
Hot Plate ◽  
Different Thickness

In this paper I present the preparation of (Sb2o3) thin films using thermal evaporation in vacuum, procedure with different thickness  (100 ,150 ,200 ,and 250) nm, by using ( hot plate) from Molybdenum matter at temperature in ( 9000c) and the period of time (15mint) ,the prepared in a manner thermal evaporation in a vacuum and precipitated on glass bases, pure Antimony Trioxide (sb2o3 ) thin films with various condition have been successfully deposited by (T.E.V) on glass slide substrates. The substrates temperature of about 100oC and the vacuum of about 10-6 torr, to investigated oxidation of evaporated, measure spectra for prepared films in arrange of wavelength (250 – 1100 nm). The following optical properties have been calculated: the absorption coefficient, the forbidden (Eg) for direct and indirect transitions "absorbance, refractive index,  extinction coefficient, real and imaginary parts" of the dielectric constant.

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

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.

Doping and Annealing Effects on the Optical Bandgap of the Nickel Doped Copper Oxide Thin Films

2021 ◽  
Vol 16 (2) ◽  
pp. 243-248
Author(s):  
Fatmah S. Bahabri ◽  
Alaa Y. Mahmoud ◽  
Wafa A. Alghameeti
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Doping Concentration ◽  
Cupric Oxide ◽  
Optical Bandgap ◽  
Visible Range ◽  
Bandgap Energy ◽  
Direct Bandgap ◽  
Annealing Temperatures ◽  
Annealing Effects

In this work, we study the optical properties of the Nickel doped cupric oxide Ni-CuO thin films with Ni various doping concentrations (0, 20, 30, 50, 70, and 80%), at two different annealing temperatures; 200 and 400 °C. The absorbance and optical bandgap for the films are calculated and compared. We find that all films exhibit clear peaks in the visible range, with the increase in the absorptivity via increasing both annealing and Ni concentration. We also find that the annealing affects the shape of the absorbance peaks to be narrowed and blue shifted. Investigation on the direct bandgap energy shows that all films exhibit large direct gap; ranging from 3.87 to 4.01 eV. For non-annealed films, direct bandgap increases with increasing the Ni concentration, while for the annealed samples, the direct bandgap generally decreases by annealing, and with increasing the doping concentration. For the indirect bandgap analysis, the calculated values of the bandgap are ranging from 0.62 to 1.96 eV. We find that for non-annealed films, the indirect bandgap increases with increasing the doping concentration, while after annealing, the bandgap decreases with increasing the doping concentration for the annealing at 200 and 400 °C, with more decreasing in the gap at 400 °C.

Optical Propagation in Solids

2006 ◽  
Author(s):  
Michael E. Thomas
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Solid State ◽  
Optical Fibers ◽  
Optical Materials ◽  
Photonic Devices ◽  
Index Of Refraction ◽  
Optical Detectors ◽  
Optical Propagation ◽  
Valence Bands

This chapter emphasizes the linear optical properties of solids as a function of frequency and temperature. Such information is basic to understanding the performance of optical fibers, lenses, dielectric and metallic mirrors, window materials, thin films, and solid-state photonic devices in general. Optical properties are comprehensively covered in terms of mathematical models of the complex index of refraction based on those discussed in Chapters 4 and 5. Parameters for these models are listed in Appendix 4. A general review of solid-state properties precedes this development because the choice of an optical material requires consideration of thermal, mechanical, chemical, and physical properties as well. This section introduces the classification of optical materials and surveys other material properties that must be considered as part of total optical system design involving solidstate optics. Solid-state materials can be classified in several ways. The following are relevant to optical materials. Three general classes of solids are insulators, semiconductors, and metals. Insulators and semiconductors are used in a variety of ways, such as lenses, windows materials, fibers, and thin films. Semiconductors are used in electrooptic devices and optical detectors. Metals are used as reflectors and high-pass filters in the ultraviolet. This type of classification is a function of the material’s electronic bandgap. Materials with a large room-temperature bandgap (Eg > 3eV) are insulators. Materials with bandgaps between 0 and 3 eV are semiconductors. Metals have no observable bandgap because the conduction and valence bands overlap. Optical properties change drastically from below the bandgap, where the medium is transparent, to above the bandgap, where the medium is highly reflective and opaque. Thus, knowledge of its location is important. Appendix 4 lists the bandgaps of a wide variety of optical materials. To characterize a medium within the region of transparency requires an understanding of the mechanisms of low-level absorption and scattering. These mechanisms are classified as intrinsic or extrinsic. Intrinsic properties are the fundamental properties of a perfect material, caused by lattice vibrations, electronic transitions, and so on, of the atoms composing the material.

Magneto-optical properties of sputter-deposited NiMnSb thin films

1997 ◽  
Vol 71 (16) ◽  
pp. 2382-2384 ◽  
Author(s):  
J. A. Caballero ◽  
W. J. Geerts ◽  
J. R. Childress ◽  
F. Petroff ◽  
P. Galtier ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Sputter Deposited
Sign in / Sign up

Export Citation Format

Share Document