A Scanning Electron and Atomic Force Microscopy Study of the Surface Morphology and Composition of CsI Films as Affected by Evaporation Rate and Humid-Air Exposure

2005 ◽  
Vol 11 (2) ◽  
pp. 124-132 ◽  
Author(s):  
Giorgio S. Senesi ◽  
Mariangela A. Nitti ◽  
Antonio Valentini
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Surface Morphology ◽  
Slow Rate ◽  
Evaporation Rate ◽  
Humid Air ◽  
Air Exposure ◽  
Force Microscopy ◽  
Atomic Force ◽  
Scanning Electron

Evaporation rate and subsequent exposure to humid air affect the surface morphology and composition of cesium iodide (CsI) films and, in turn, their photoemissive efficiency when used as photocathodes. The surface morphology and elemental composition of 300-nm-thick CsI films grown at two different rates (1 nm/s and 0.04 nm/s), both freshly evaporated and after 24-h exposure to humid air were investigated by means of atomic force microscopy and scanning electron microscopy/electron diffraction spectroscopy. The CsI film freshly evaporated at a slow rate exhibited a granular surface presenting circular holes or craters where the CsI material was moved from the center to the boundaries. After 24-h exposure to humid air, this film coalesced in large grain showing a marked increase of surface roughness. Conversely, the CsI film grown at a fast rate mostly retained its original surface uniformity and homogeneity with no presence of holes and craters after 24-h exposure to humid air. Further, surface roughness and average peak height decreased, but the surface coalesced in large grains spaced by small fractures where the CsI coverage was almost lost. In conclusion, the films grown at a fast evaporation rate were affected by 24-h exposure to humid air less than those grown at a slow rate, and are thus expected to possess a greater long-term stability.

scholarly journals Comparison of the Enamel Surface Roughness from Different Polishing Methods: Scanning Electron Microscopy and Atomic Force Microscopy Investigation

2020 ◽  
Vol 14 (02) ◽  
pp. 299-305
Author(s):  
Kiatanan Sugsompian ◽  
Ratchawan Tansalarak ◽  
Thosapol Piyapattamin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Enamel Surface ◽  
Similar Data ◽  
Force Microscopy ◽  
Atomic Force ◽  
Significant Difference ◽  
Scanning Electron

Abstract Objective This study aimed to compare the enamel surface roughness created by four polishing methods after debonding, by using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Materials and Methods Four experimental polishing groups (Sof-Lex disc, SD; sandblaster, SB; tungsten carbide bur, TB; and white stone bur, WB) and one control group were selected from 100 premolars (n = 20/group). The experimental teeth were bonded with a bracket, thermocycled, and debonded. Residual adhesive was removed by either of the respective methods. Pre and postdebonding root mean square (Rq) values were obtained from AFM evaluations. All specimens were examined and evaluated with SEM using a modified enamel surface index (modified ESI). Statistical Analysis Differences among the polishing methods were compared with analysis of variance and Fisher’s least significant difference test at p < 0.05. Results Both microscopic evaluations indicated that the surface with the greatest roughness herein belonged to the SD group, followed by that for SB, TB, and WB groups. AFM measurements indicated a maximum postdebonding Rq herein for the WB group and a significantly greater surface roughness for the TB and WB groups than for the SD and SB groups. Among the experimental groups, SEM followed by modified ESI evaluations revealed similar data to those obtained with AFM. Significant differences were seen among all paired groups, except for that between the SB and TB groups. Conclusion Within the limitations of this study, all four polishing methods were concluded to be clinically acceptable for removing residual orthodontic adhesives.

Growth of Germanium on Porous Silicon (001)

1996 ◽  
Vol 452 ◽  
Author(s):  
W. H. Thompson ◽  
Z. Yamani ◽  
H. M. Nayfeh ◽  
M.-A. Hasan ◽  
J. E. Greene ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Porous Silicon ◽  
Molecular Beam Epitaxy ◽  
Surface Morphology ◽  
Molecular Beam ◽  
Porous Si ◽  
Force Microscopy ◽  
Atomic Force ◽  
Nm Range

AbstractThe surface morphology of Ge grown on Si (001) and porous Si(001) by molecular beam epitaxy at 380 °C is examined using atomic force microscopy (AFM). For layer thicknesses of 30 nm, the surface shows islanding while still maintaining some of the underlying roughness of the surface of porous Si. For thicknesses in the 100 nm range, the surface roughness is not visible, but the islanding persists. Unlike the case of silicon where islands tend to merge and nearly disappear as the thickness of the deposited layer rises, we observe on the porous layer the persistence of the islands with no merging even for macroscopic thicknesses as large as 0.73 microns.

Mitigation of BPD by Pre-Epigrowth High Temperature Substrate Annealing

2016 ◽  
Vol 858 ◽  
pp. 233-236 ◽  
Author(s):  
Nadeemullah A. Mahadik ◽  
Robert E. Stahlbush ◽  
Eugene A. Imhoff ◽  
M.J. Tadjer ◽  
G.E. Ruland ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
High Temperature ◽  
Surface Morphology ◽  
Substrate Surface ◽  
High Temperature Annealing ◽  
Force Microscopy ◽  
Atomic Force ◽  
Substrate Annealing ◽  
Edge Dislocations

Basal Plane Dislocations (BPD) intersecting the SiC substrate surface were converted to threading edge dislocations (TED) by high temperature annealing of the substrates in the temperature range of 1750 °C – 1950 °C. Successively, epitaxial growth on annealed as well as non-annealed samples was performed, concurrently, to investigate the effect of the substrate annealing on BPD mitigation in the epilayers. For the 1950 °C/10min anneal, a 3x reduction in BPD density was observed. Additionally, surface roughness measured using atomic force microscopy revealed no degradation in surface morphology of the grown epilayers after annealing.

Effect of Borax Content on Composition and Microstructure of Boride Layer by Electrodeposition

2011 ◽  
Vol 179-180 ◽  
pp. 508-512 ◽  
Author(s):  
Hai Li Yang ◽  
Ning He ◽  
Guo Zhang Tang ◽  
Yun Gang Li ◽  
Yu Zhu Zhang
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Glow Discharge ◽  
Surface Morphology ◽  
Molten Salts ◽  
Boride Layer ◽  
Silicon Steel ◽  
Force Microscopy ◽  
Atomic Force ◽  
Compositional Depth Profile

Boronizing of silicon steel is performed by electrodeposition in KCl-NaCl-NaF-Na2B4O710H2O molten salts with different amounts of borax. The effect of borax content on composition and microstructure of boride layer is studied. The compositional depth profile of boride layer is measured using the glow discharge spectrometry (GDS) and the depth from the surface to the substrate is taken as the layer thickness. The surface morphology is studied by atomic force microscopy (AFM). It is found that the thickness of the boride layer reached maximum values when the borax content is 0.05mol. The roughness decreases with raising borax content from 0.01 to 0.05mol while the further increase of borax content from 0.05 to 0.1mol results in increase of roughness. The boride layer formed at borax content 0.05 mol shows smallest values of surface roughness.

A COMPARISON BETWEEN THE ATOMIC FORCE MICROSCOPY AND X-RAY REFLECTIVITY ON THE CHARACTERIZATION OF SURFACE ROUGHNESS

2003 ◽  
Vol 02 (04n05) ◽  
pp. 343-348 ◽  
Author(s):  
CHIH-HAO LEE ◽  
WEN-YEN PEN ◽  
MING-ZHE LIN ◽  
KUAN-LI YU ◽  
JEN-CHUNG HSUEH
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Surface Morphology ◽  
Power Spectra ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Roughness Exponent ◽  
Buried Layer

Atomic force microscopy and X-ray reflectivity methods are used to characterize a surface morphology which includes the information of rms roughness, roughness exponent, and the height–height correlation length. Two major reasons to interpret the discrepancy of rms roughness data measured by AFM and X-ray reflectivity are (1) the bandpass of power spectra density is different and (2) the X-ray reflectivity probes the high density buried layer.

Brittle Behaviour in Aspirin Crystals: Evidence of Spalling Fracture

2020 ◽  
Author(s):  
Benjamin P. A. Gabriele ◽  
Craig J. Williams ◽  
Douglas Stauffer ◽  
Brian Derby ◽  
Aurora J. Cruz-Cabeza
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Single Crystals ◽  
Spalling Fracture ◽  
Force Microscopy ◽  
Atomic Force ◽  
Afm Imaging

<div> <div> <div> <p>Single crystals of aspirin form I were cleaved and indented on their dominant face. Upon inspection, it was possible to observe strongly anisotropic shallow lateral cracks due to the extreme low surface roughness after cleavage. Atomic Force Microscopy (AFM) imaging showed spalling fractures nucleating from the indent corners, forming terraces with a height of one or two interplanar spacings d100. The formation of such spalling fractures in aspirin was rationalised using basic calculations of attachment energies, showing how (100) layers are poorly bonded when compared to their relatively higher intralayer bonding. An attempt at explaining the preferential propagation of these fractures along the [010] direction is discussed. </p> </div> </div> </div>

Brittle Behaviour in Aspirin Crystals: Evidence of Spalling Fracture

2020 ◽  
Author(s):  
Benjamin P. A. Gabriele ◽  
Craig J. Williams ◽  
Douglas Stauffer ◽  
Brian Derby ◽  
Aurora J. Cruz-Cabeza
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Single Crystals ◽  
Spalling Fracture ◽  
Force Microscopy ◽  
Atomic Force ◽  
Afm Imaging

<div> <div> <div> <p>Single crystals of aspirin form I were cleaved and indented on their dominant face. Upon inspection, it was possible to observe strongly anisotropic shallow lateral cracks due to the extreme low surface roughness after cleavage. Atomic Force Microscopy (AFM) imaging showed spalling fractures nucleating from the indent corners, forming terraces with a height of one or two interplanar spacings d100. The formation of such spalling fractures in aspirin was rationalised using basic calculations of attachment energies, showing how (100) layers are poorly bonded when compared to their relatively higher intralayer bonding. An attempt at explaining the preferential propagation of these fractures along the [010] direction is discussed. </p> </div> </div> </div>

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