Stress-induced surface characterization by wavelet and fractal analysis in Ga-doped ZnO thin films

MRS Advances ◽  
2017 ◽  
Vol 2 (53) ◽  
pp. 3105-3110
Author(s):  
Chenlei Jing ◽  
Yang Hu ◽  
Wu Tang

ABSTRACTThe Ga-doped ZnO (GZO) were deposited by magnetron reactive sputtering on glass substrates at room temperature with different deposited times to obtain various thickness. The root-mean-square (RMS) roughness obtained from the atomic force microscopy (AFM) images is observed to shift linearly with the deposited time, the fractal geometry and multi-resolution signal decomposition (MRSD) based on wavelet transform were applied on the surface profiles and the results does not synchronously changes as the thickness, which is related to the profile’s frequency. The calculated compressive in-plane stress of highly c-axis oriented GZO films also shows an irregular variation as the increase of film thickness, what’s more, the in-plane stress and fractal dimension exhibit a polynomial relationship and the two parameters can be used for describing the surface morphology.

2005 ◽  
Vol 12 (05n06) ◽  
pp. 759-766 ◽  
Author(s):  
MUHAMMAD MAQBOOL ◽  
TAHIRZEB KHAN

Thin films of pure silver were deposited on glass substrate by thermal evaporation process at room temperature. Surface characterization of the films was performed using X-ray diffraction (XRD) and Atomic Force Microscopy (AFM). Thickness of the films varied between 20 nm and 60 nm. XRD analysis provided a sharp peak at 38.75° from silver. These results indicated that the films deposited on glass substrates at room temperature are crystalline. 3D and top view pictures of the films were obtained by AFM to study the grain size and its dependency on various factors. Grain sizes were calculated using the XRD results and Scherer's formula. Average grain size increased with the thickness of the deposited films. A minimum grain size of 8 nm was obtained for 20 nm thick films, reaching a maximum value of 41.9 nm when the film size reaches 60 nm. We could not find any sequential variation in the grain size with the growth rate.


2006 ◽  
Vol 20 (02) ◽  
pp. 217-231 ◽  
Author(s):  
MUHAMMAD MAQBOOL ◽  
TAHIRZEB KHAN

Thin films of pure silver were deposited on glass substrate by thermal evaporation process at room temperature. Surface characterization of the films was performed using X-ray diffraction (XRD) and atomic force microscopy (AFM). Thickness of the films varied between 20 nm and 72.8 nm. XRD analysis provided a sharp peak at 38.75° from silver. These results indicated that the films deposited on glass substrates at room temperature are crystalline. Three-dimension and top view pictures of the films were obtained by AFM to study the grain size and its dependency on various factors. Average grain size increased with the thickness of the deposited films. A minimum grain size of 8 nm was obtained for 20 nm thick films, reaching 41.9 nm when the film size reaches 60 nm. Grain size was calculated from the information provided by the XRD spectrum and averaging method. We could not find any sequential variation in the grain size with the growth rate.


2016 ◽  
Vol 721 ◽  
pp. 394-398 ◽  
Author(s):  
Anzelms Zukuls ◽  
Gundars Mezinskis

Fe2O3–TiO2 coatings were successfully prepared on glass slide substrates using sol–gel method for wettability applications. The microstructure and surface properties of the coatings were extensively characterized by using X-ray diffractometry (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Different solutions were prepared by adding distilled water to sol solution. Glass substrates were coated by solutions of Ti-alkoxide, Fe-chloride hexahydrate, ethylene glycol, acetic acid, isopropanol and glycerol. The obtained gel films were dried at room temperature for 15 min in air. The oxide thin films were annealed at 500 ºC for 1h. The influence of distilled water concentration and withdraw speed on contact angle of the films was established. In addition, XRD results revealed that Fe2O3–TiO2 films composed of anatase, rutile, brookite and hematite phases. The purpose of this contribution was the investigation of different preparation parameters during the synthesis of iron oxide rich Fe2O3–TiO2 thin hydrophobic films on glass substrate. SEM and AFM observations revealed leaf-like structure formation on a coating surface.


e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Débora Gonçalves ◽  
Silmar A. Travain ◽  
José A. Giacometti ◽  
Eugene A. Irene

AbstractPANI films were deposited on glass substrates by in-situ polymerization and characterized by UV-VIS spectroscopy and atomic force microscopy. A method is developed to accurately analyze ellipsometric data obtained for transparent glass substrates before and after modification with absorbing polymer films. Surface modification was made with an overlayer such as polyaniline (PANI), which exhibits different optical properties by varying its oxidation state. First, the issue of using transparent substrates for ellipsometry studies was examined and then, spectroscopic ellipsometry was used to characterize absorbing overlayers on transparent glasses. The same methodologies of data analysis can be also applied to other absorbing films on transparent substrates, and deposited by different techniques


2012 ◽  
Vol 557-559 ◽  
pp. 1787-1790
Author(s):  
Jia Ling Xu ◽  
Li Yun Jia ◽  
Hong Fan

C/FePt/Ti nano-thin films were prepared by DC facing-target magnetron sputtering system onto glass substrates at room temperature and subsequently in situ annealed for 500 °C 30 min in vacuum. The influence of C capping layer on microstructural and magnetic properties of the FePt films were investigated in detail. Atomic force microscopy (AFM) images indicate that C can effectively isolate the particles, refine particle, and distribute; however, the particle size distribution is uneven for too much C. The easy magnetic axial orientation is changed with the C layer thickness.


2018 ◽  
Vol 64 (6) ◽  
pp. 655
Author(s):  
J. Eduardo Rivera L. ◽  
Narcizo Muñoz A. ◽  
Juliana G. Gutiérrez-Paredes ◽  
Pedro A. Tamayo-Meza ◽  
Alejandro Alvarez Z. ◽  
...  

By means of the I-V characteristics measured at room temperature, the height of the Schottky barrier established by the conductive Pt-Ir tip of an Atomic Force Microscope on the aluminum doped ZnO thin films were estimated in the range of 0.58-0.64 eV. The ideality factors were in the range of  2.11-1.39, respectively. These values are in accordance with those reported by other authors that measured the height of the Pt Schottky barrier on ZnO by means of several methods. The procedure detailed in this work suggests that the scanning time for obtaining I-V Schottky characteristics is of the order of 2 ms.


Author(s):  
K. A. Fisher ◽  
M. G. L. Gustafsson ◽  
M. B. Shattuck ◽  
J. Clarke

The atomic force microscope (AFM) is capable of imaging electrically conductive and non-conductive surfaces at atomic resolution. When used to image biological samples, however, lateral resolution is often limited to nanometer levels, due primarily to AFM tip/sample interactions. Several approaches to immobilize and stabilize soft or flexible molecules for AFM have been examined, notably, tethering coating, and freezing. Although each approach has its advantages and disadvantages, rapid freezing techniques have the special advantage of avoiding chemical perturbation, and minimizing physical disruption of the sample. Scanning with an AFM at cryogenic temperatures has the potential to image frozen biomolecules at high resolution. We have constructed a force microscope capable of operating immersed in liquid n-pentane and have tested its performance at room temperature with carbon and metal-coated samples, and at 143° K with uncoated ferritin and purple membrane (PM).


2010 ◽  
Vol 663-665 ◽  
pp. 324-327
Author(s):  
Chao Song ◽  
Rui Huang

The germanium film and Ge/Si multilayer structure were fabricated by magnetron sputtering technique on silicon substrate at temperatures of 500°C. Raman scattering spectroscopy measurements reveal that the nanocrystalline Ge occurs in both kinds of samples. Furthermore, from the atomic force microscopy (AFM) results, it is found that the grain size as well as spatially ordering distribution of the nc-Ge can be modulated by the Ge/Si multilayer structure. The room temperature photoluminescence was also observed in the samples. However, compared with that from the nc-Ge film, the intensity of PL from the nc-Ge/a-Si multilayer film becomes weaker, which is attributed to its lower volume fraction of crystallized component.


Author(s):  
Lin Zhang ◽  
Bai An ◽  
Takashi Iijima ◽  
Chris San Marchi ◽  
Brian Somerday

The behaviors of hydrogen transport and hydrogen-assisted cracking in hydrogen-precharged SUS304 austenitic stainless steel sheets in a temperature range from 177 to 298 K are investigated by a combined tensile and hydrogen release experiment as well as magnetic force microscopy (MFM) based on atomic force microscopy (AFM). It is observed that the hydrogen embrittlement increases with decreasing temperature, reaches a maximum at around 218 K, and then decreases with further temperature decrease. The hydrogen release rate increases with increasing strain until fracture at room temperature but remains near zero level at and below 218 K except for some small distinct release peaks. The MFM observations reveal that fracture occurs at phase boundaries along slip planes at room temperature and twin boundaries at 218 K. The role of strain-induced martensite in the hydrogen transport and hydrogen embrittlement is discussed.


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