Fluence-dependent sputtering yield measurement, surface morphology, crater depth, and hardness of laser-irradiated Zr in N2 and Ne environments

2019 ◽  
Vol 36 (7) ◽  
pp. 1945 ◽  
Author(s):  
Syed Muhammad Abouzar Sarfraz ◽  
Shazia Bashir ◽  
Khaliq Mahmood ◽  
Aniqa Khaliq ◽  
Rabia Rizvi
1989 ◽  
Vol 7 (1) ◽  
pp. 21-26 ◽  
Author(s):  
W. K. Leung ◽  
Y. Hirooka ◽  
R. W. Conn ◽  
D. M. Goebel ◽  
B. Labombard ◽  
...  

2019 ◽  
Vol 37 (01) ◽  
pp. 128-140 ◽  
Author(s):  
Syed Muhammad Abouzar Sarfraz ◽  
Shazia Bashir ◽  
Khaliq Mahmood

AbstractThe effect of laser fluence and nature of ambient environments on the sputtering yield, surface modifications, crater depth, UV-visible absorption spectra, chemical composition, and micro hardness of Zr has been investigated. Nd: YAG laser (532 nm, 10 Hz, 6 ns) at different fluences varying from 16 to 60.8 Jcm−2 was employed as an irradiation source. All measurements are performed under two ambient environments of Ar and O2 at a constant pressure of 10 Torr. Quartz crystal microbalance has been employed for the measurement of sputtering yield of laser irradiated Zr. It is revealed that sputtering yield increases monotonically with increasing fluence under both environments however, it is higher in Ar as compared to O2 environment. Scanning electron microscope (SEM) has been used to explore the surface morphology. SEM analysis exhibits the formation of cones, ridges, and cracks at the central ablated areas whereas, laser-induced periodic surface structures, periodic ridges and sharp cones are observed at inner boundaries in both environments of Ar and O2. Sharp spikes are observed in both environments, however, their height and distinctness are more pronounced in Ar as compared to O2. Cones are characteristic features in Ar, whereas, cavities and channels are dominant features in O2 environment at outer boundaries. The formation and growth of surface structures are dependent upon laser fluence and ambient gas nature. The depth profilometry has been used to measure the crater depth of irradiated Zr target by using an optical microscope. UV visible spectroscopy and energy-dispersive X-ray analyses reveal the oxide formation in the case of Zr irradiation in O2 environment. The Vicker Micro-hardness tester has been employed to measure the hardness. The higher observed values of sputtering yield, crater depth and hardness of laser ablated Zr in Ar as compared to O2 are well correlated with distinct surface structures.


1988 ◽  
Author(s):  
W.K. Leung ◽  
Y. Hirooka ◽  
R.W. Conn ◽  
D.M. Goebel ◽  
B. LaBombard ◽  
...  

Author(s):  
Li C.L. ◽  
Chew E.C. ◽  
Huang D.P. ◽  
Ho H.C. ◽  
Mak L.S. ◽  
...  

An epithelial cell line, NPC/HK1, has recently been successfully established from a nasopharyngeal carcinoma of the moderately to well differentiated squamous type. The present communication reports on the surface morphology of the NPC/HK1 cells in culture.


Author(s):  
J. Temple Black ◽  
Jose Guerrero

In the SEM, contrast in the image is the result of variations in the volume secondary electron emission and backscatter emission which reaches the detector and serves to intensity modulate the signal for the CRT's. This emission is a function of the accelerating potential, material density, chemistry, crystallography, local charge effects, surface morphology and especially the angle of the incident electron beam with the particular surface site. Aside from the influence of object inclination, the surface morphology is the most important feature In producing contrast. “Specimen collection“ is the name given the shielding of the collector by adjacent parts of the specimen, producing much image contrast. This type of contrast can occur for both secondary and backscatter electrons even though the secondary electrons take curved paths to the detector-collector.Figure 1 demonstrates, in a unique and striking fashion, the specimen collection effect. The subject material here is Armco Iron, 99.85% purity, which was spark machined.


Author(s):  
D.R. Mattie ◽  
J.W. Fisher

Jet fuels such as JP-4 can be introduced into the environment and come in contact with aquatic biota in several ways. Studies in this laboratory have demonstrated JP-4 toxicity to fish. Benzene is the major constituent of the water soluble fraction of JP-4. The normal surface morphology of bluegill olfactory lamellae was examined in conjunction with electrophysiology experiments. There was no information regarding the ultrastructural and physiological responses of the olfactory epithelium of bluegills to acute benzene exposure.The purpose of this investigation was to determine the effects of benzene on the surface morphology of the nasal rosettes of the bluegill sunfish (Lepomis macrochirus). Bluegills were exposed to a sublethal concentration of 7.7±0.2ppm (+S.E.M.) benzene for five, ten or fourteen days. Nasal rosettes were fixed in 2.5% glutaraldehyde and 2.0% paraformaldehyde in 0.1M cacodylate buffer (pH 7.4) containing 1.25mM calcium chloride. Specimens were processed for scanning electron microscopy.


Author(s):  
N. Osakabe ◽  
J. Endo ◽  
T. Matsuda ◽  
A. Tonomura

Progress in microscopy such as STM and TEM-TED has revealed surface structures in atomic dimension. REM has been used for the observation of surface dynamical process and surface morphology. Recently developed reflection electron holography, which employes REM optics to measure the phase shift of reflected electron, has been proved to be effective for the observation of surface morphology in high vertical resolution ≃ 0.01 Å.The key to the high sensitivity of the method is best shown by comparing the phase shift generation by surface topography with that in transmission mode. Difference in refractive index between vacuum and material Vo/2E≃10-4 owes the phase shift in transmission mode as shownn Fig. 1( a). While geometrical path difference is created in reflection mode( Fig. 1(b) ), which is measured interferometrically using high energy electron beam of wavelength ≃0.01 Å. Together with the phase amplification technique , the vertivcal resolution is expected to be ≤0.01 Å in an ideal case.


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