AFM Study of Magnetron Sputtered Nickel Films Coated on Cenosphere Particles

2015 ◽  
Vol 713-715 ◽  
pp. 2585-2589
Author(s):  
Xiao Zheng Yu

The morphologies of nanocrystalline nickel film coated on cenosphere particles using magnetron sputtering method were investigated by atomic force microscopy (AFM). The AFM results show the grain sizes and root-mean-square (RMS) roughness values of nickel films increase with the increase of sputtering power or deposition time and the nickel films growth is a three-dimensional island growth mode. The unceasingly variational angular distribution can get rid of the physical shadowing effect of the sputtering and promote a rather smooth film growth. Due to the all-around effect, the final distribution of grains shows a rather smooth morphology with low roughness.


2011 ◽  
Vol 493-494 ◽  
pp. 473-476
Author(s):  
E.O. Lopez ◽  
F.F. Borghi ◽  
Alexandre Mello ◽  
J. Gomes ◽  
Antonella M. Rossi

In this present work, we characterize HAp thin films deposited by dual magnetron sputtering device DMS on silicon (Si/HAp). The sputtering RF power was varied from 90 watts to 120 watts and deposition times from 60 to 180 minutes. The argon and oxygen pressure were fixed at 5.0 mTorr and 1.0 mTorr, respectively. Grazing incidence X-ray diffraction (GIXRD) from synchrotron radiation, infrared spectroscopy (FTIR) and atomic force microscopy (AFM) were used for the structural characterization. At lower deposition times, a crystalline phase with preferential orientation along apatite (002) and a disordered nanocrystalline phase were identified. The coating crystallinity was improved with the increase of the deposition time besides the sputtering power.



2011 ◽  
Vol 399-401 ◽  
pp. 1984-1988
Author(s):  
Hai Li Yang ◽  
Li Wu ◽  
Guo Zhang Tang ◽  
Yun Gang Li ◽  
Yu Zhu Zhang

Fe-Si layer was prepared on silicon steel substrate from KCl-NaCl-NaF-SiO2 molten salts by pulse current at different time. The quantitative Si concentration depth profile, surface morphology and phase structure of the layer were studied by glow discharge optical emission spectroscopy, atomic force microscopy and X-ray diffraction. The layer growing process was analyzed from nucleation process, growth pattern and microstructure. It was observed that the Fe-Si alloy nucleated in the way of three dimensional conical shape and initially grew in the orientation of matrix, then gradually adjusted to the lowest energy state. With deposition time going on, the phase structure of the layer changed in the order of -Fe (Si) →α-Fe (Si) +Fe3Si →Fe3Si



2001 ◽  
Vol 693 ◽  
Author(s):  
Peter Miraglia ◽  
Edward Preble ◽  
Amy Roskowski ◽  
Sven Einfeldt ◽  
Robert F. Davis

AbstractThe surface morphologies of GaN and InGaN films grown at 780°C by metalorganic vapor phase epitaxy were determined using atomic force microscopy. A qualitative model is presented to explain observed instabilities in the step morphology of these films, namely, the formation of hillock islands and v-defects that give rise to surface roughening. The latter are a result of a boundary dragging effect, where interactions occur between the movement of homogeneous and heterogeneous steps and the tendency to form atom clusters in the terrace in the transition in kinetic growth regime. The tendency to form v-defects was associated with dislocation density. A delay in the formation of v-defects in InGaN was observed and associated with the ammonia partial pressure and the interactions between hillock islands and pure screw or mixed dislocations. Hillock island formation was attributed to a transition in thermodynamic mode to three-dimensional island growth. Explanations for the foregoing observations are based on growth model theory previously developed by Burton, Cabrera, and Frank (BCF) and on changes in the surface kinetics with temperature, In composition, and gas phase composition.



2016 ◽  
Vol 7 ◽  
pp. 102-110 ◽  
Author(s):  
Nina J Blumenstein ◽  
Caroline G Hofmeister ◽  
Peter Lindemann ◽  
Cheng Huang ◽  
Johannes Baier ◽  
...  

In this study we investigated the influence of an organic polystyrene brush on the deposition of ZnO thin films under moderate conditions. On a non-modified SiO x surface, island growth is observed, whereas the polymer brush induces homogeneous film growth. A chemical modification of the polystyrene brushes during the mineralization process occurs, which enables stronger interaction between the then polar template and polar ZnO crystallites in solution. This may lead to oriented attachment of the crystallites so that the observed (002) texture arises. Characterization of the templates and the resulting ZnO films were performed with ζ-potential and contact angle measurements as well as scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD). Infrared spectroscopy (IR) measurements were used to investigate the polystyrene brushes before and after modification.



2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Marcio N. Gomes ◽  
Jackeline B. Brito ◽  
Josmary R. Silva ◽  
Nara C. de Souza

We report on the preparation and study of layer-by-layer films of wine alternated with bovine serum albumin (BSA). We found that the exponential and/or linear growth of the films is dependent on the deposition time. Atomic force microscopy images were analysed using scale laws and the fractal dimension, and the results suggested that the BSA/wine film growth regime is determined by sub-bilayer or bilayer growth. Exponential growth was associated with a sub-bilayer deposition regime, whereas linear growth was associated with a bilayer deposition in which a constant amount of material is deposited.



2021 ◽  
Vol 129 (3) ◽  
pp. 030901
Author(s):  
Hossein J. Sharahi ◽  
Mohsen Janmaleki ◽  
Laurene Tetard ◽  
Seonghwan Kim ◽  
Hamed Sadeghian ◽  
...  


2021 ◽  
Vol 50 (2) ◽  
pp. 223-237 ◽  
Author(s):  
Hannes Witt ◽  
Filip Savić ◽  
Sarah Verbeek ◽  
Jörn Dietz ◽  
Gesa Tarantola ◽  
...  

AbstractMembrane-coated colloidal probes combine the benefits of solid-supported membranes with a more complex three-dimensional geometry. This combination makes them a powerful model system that enables the visualization of dynamic biological processes with high throughput and minimal reliance on fluorescent labels. Here, we want to review recent applications of colloidal probes for the study of membrane fusion. After discussing the advantages and disadvantages of some classical vesicle-based fusion assays, we introduce an assay using optical detection of fusion between membrane-coated glass microspheres in a quasi two-dimensional assembly. Then, we discuss free energy considerations of membrane fusion between supported bilayers, and show how colloidal probes can be combined with atomic force microscopy or optical tweezers to access the fusion process with even greater detail.



2001 ◽  
Vol 673 ◽  
Author(s):  
A. Maxwell Andrews ◽  
J.S. Speck ◽  
A.E. Romanov ◽  
M. Bobeth ◽  
W. Pompe

ABSTRACTAn approach is developed for understanding the cross-hatch morphology in lattice mismatched heteroepitaxial film growth. It is demonstrated that both strain relaxation associated with misfit dislocation formation and subsequent step elimination (e.g. by step-flow growth) are responsible for the appearance of nanoscopic surface height undulations (0.1-10 nm) on a mesoscopic (∼100 nm) lateral scale. The results of Monte Carlo simulations for dislocation- assisted strain relaxation and subsequent film growth predict the development of cross-hatch patterns with a characteristic surface undulation magnitude ∼50 Å in an approximately 70% strain relaxed In0.25Ga0.75As layers. The model is supported by atomic force microscopy (AFM) observations of cross-hatch morphology in the same composition samples grown well beyond the critical thickness for misfit dislocation generation.



2017 ◽  
Vol 23 (3) ◽  
pp. 661-667 ◽  
Author(s):  
Yue Li ◽  
Di Zhang ◽  
Ilker Capoglu ◽  
Karl A. Hujsak ◽  
Dhwanil Damania ◽  
...  

AbstractEssentially all biological processes are highly dependent on the nanoscale architecture of the cellular components where these processes take place. Statistical measures, such as the autocorrelation function (ACF) of the three-dimensional (3D) mass–density distribution, are widely used to characterize cellular nanostructure. However, conventional methods of reconstruction of the deterministic 3D mass–density distribution, from which these statistical measures can be calculated, have been inadequate for thick biological structures, such as whole cells, due to the conflict between the need for nanoscale resolution and its inverse relationship with thickness after conventional tomographic reconstruction. To tackle the problem, we have developed a robust method to calculate the ACF of the 3D mass–density distribution without tomography. Assuming the biological mass distribution is isotropic, our method allows for accurate statistical characterization of the 3D mass–density distribution by ACF with two data sets: a single projection image by scanning transmission electron microscopy and a thickness map by atomic force microscopy. Here we present validation of the ACF reconstruction algorithm, as well as its application to calculate the statistics of the 3D distribution of mass–density in a region containing the nucleus of an entire mammalian cell. This method may provide important insights into architectural changes that accompany cellular processes.





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