scholarly journals In-situ biaxial texture analysis of MgO films during growth on amorphous substrates by ion-beam-assisted deposition

2001 ◽  
Author(s):  
Rhett Brewer ◽  
Paul N. Arendt ◽  
James R. Groves ◽  
Harry A. Atwater
Keyword(s):  
Texture Analysis ◽  
Ion Beam ◽  
Biaxial Texture ◽  
Ion Beam Assisted Deposition ◽  
Amorphous Substrates

scholarly journals In Situ Biaxial Texture Analysis of Mgo Films During Growth on Amorphous Substrates by Ion Beam-Assisted Deposition

2001 ◽  
Vol 672 ◽  
Author(s):  
Rhett T. Brewer ◽  
Paul N. Arendt ◽  
James R. Groves ◽  
Harry A. Atwater
Keyword(s):  
Film Thickness ◽  
Ion Beam ◽  
Orientation Distribution ◽  
X Ray ◽  
Biaxial Texture ◽  
Plane Orientation ◽  
Transmission Electron ◽  
Out Of Plane ◽  
Amorphous Substrates

ABSTRACTWe used a previously reported kinematical electron scattering model1 to develop a RHEED based method for performing quantitative analysis of mosaic polycrystalline thin film in-plane and out-of-plain grain orientation distributions. RHEED based biaxial texture measurements are compared to X-Ray and transmission electron microscopy measurements to establish the validity of the RHEED analysis method. In situ RHEED analysis reveals that the out-of-plane orientation distribution starts out very broad, and then decreases during IBAD MgO growth. Other results included evidence that the in-plane orientation distribution narrows, the grain size increases, and the film roughens as film thickness increases during IBAD MgO growth. Homoepitaxy of MgO improves the biaxial texture of the IBAD layer, making X-ray measurements of IBAD films with an additional homoepitaxial layer not quantitatively representative of the IBAD layer. Systematic offsets between RHEED analysis and X-ray measurements of biaxial texture, coupled with evidence that biaxial texture improves with increasing film thickness, indicate that RHEED is a superior technique for probing surface biaxial texture.

A study on functionally graded HA coatings processed using ion beam assisted deposition with in situ heat treatment

2006 ◽  
Vol 200 (20-21) ◽  
pp. 6111-6116 ◽  
Author(s):  
A. Rabiei ◽  
B. Thomas ◽  
C. Jin ◽  
R. Narayan ◽  
J. Cuomo ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Ion Beam ◽  
Functionally Graded ◽  
Ion Beam Assisted Deposition ◽  
In Situ Heat Treatment

scholarly journals Surface-Treated versus Untreated Large-Bore Catheters as Vascular Access in Hemodialysis and Apheresis Treatments

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Rolf Bambauer ◽  
Ralf Schiel ◽  
Carolin Bambauer ◽  
Reinhard Latza
Keyword(s):  
Electron Microscope ◽  
Retrospective Study ◽  
Outer Surface ◽  
Bacterial Colonization ◽  
Ion Beam ◽  
Treatment Processes ◽  
Ion Beam Assisted Deposition ◽  
Biological Surface ◽  
Scanning Electron

Background. Catheter-related infections, thrombosis, and stenosis are among the most frequent complications associated with catheters, which are inserted in vessels. Surface treatment processes of the outer surface, such as ion-beam-assisted deposition, can be used to mitigate such complications.Methods. This retrospective study (1992–2007) evaluated silver-coated (54 patients) and noncoated (105 patients) implanted large-bore catheters used for extracorporeal detoxification. The catheters were inserted into the internal jugular or subclavian veins. After removal, the catheters were cultured for bacterial colonization using standard microbiologic assays. They also were examined using scanning electron microscope.Results. The silver coated catheters showed a tendency towards longer in situ time. The microbiologic examinations of the catheter tips were in both catheter types high positive, but not significant.Conclusion. The silver-coated catheters showed no significantly reduction in infection rate by evaluation of all collected data in this retrospective study. There was no association between both catheters in significantly reducing savings in treatment costs and in reducing patient discomfort. Other new developed catheter materials such as the microdomain-structured inner and outer surface are considered more biocompatible because they mimic the structure of natural biological surface.

Role of beam divergence and ion-to-molecule flux ratio in ion-beam-assisted deposition texturing of MgO

2004 ◽  
Vol 19 (2) ◽  
pp. 501-504 ◽  
Author(s):  
Alp T. Findikoglu ◽  
Sascha Kreiskott ◽  
Paul M. te Riele ◽  
Vladimir Matias
Keyword(s):  
Ion Beam ◽  
Strong Dependence ◽  
Flux Ratio ◽  
Fused Silica ◽  
Process Conditions ◽  
Semiconductor Films ◽  
Si Substrates ◽  
Biaxial Texture ◽  
Ion Beam Assisted Deposition ◽  
Out Of Plane

The effect of process conditions on the biaxial texture of MgO films grown by ion-beam-assisted deposition (IBAD) was studied. The texture showed a strong dependence on the Ar+/MgO flux ratio, but a weak dependence on the divergence of Ar+ beam. One hundred-nanometer-thick epi-MgO on less than 10-nm-thick textured IBAD-MgO films that were grown on 7-nm-thick Y2O3 layers on fused silica, metal alloy tape, and polished Si substrates showed biaxial texture with in- and out-of-plane orientation distributions of less than 4° and 2°, respectively. These results strengthen the notion that the IBAD technique could serve as a universal technological process to integrate amorphous and polycrystalline substrates with various oxide and semiconductor films that need to be grown with good biaxial texture.

Quantitative Rheed Analysis of Biaxially-Textured Polycrystalline MgO Films on Amorphous Substrates Grown by Ion Beam-Assisted Deposition

1999 ◽  
Vol 585 ◽  
Author(s):  
R. T. Brewer ◽  
J. W. Hartman ◽  
Harry A. Atwater
Keyword(s):  
Crystallographic Texture ◽  
Incidence Angle ◽  
Ion Beam ◽  
Orientation Distribution ◽  
High Energy ◽  
Polycrystalline Films ◽  
Plane Orientation ◽  
Ion Beam Assisted Deposition ◽  
Kinematic Approximation ◽  
Amorphous Substrates

AbstractWe have developed a computer simulation based on analytic calculation of reflection high energy electron diffraction (RHEED) patterns in the kinematic approximation for mosaic polycrystalline films for given values of electron beam incidence angle, polycrystalline texture, in-plane orientation distribution, and grain size. Although RHEED is most appropriately modeled using dynamical scattering theory, the computational efficiency of the kinematic approximation has enabled the development of a model suitable for real time measurement of crystallographic texture and in-plane orientation distributions for biaxially-textured films grown by ion beam-assisted deposition (IBAD). Using the simulation, we can quantitatively determine how RHEED spot shapes and relative intensities depend on the crystallographic texture and in-plane orientation distribution of polycrystalline films. RHEED patterns taken at 25 keV with incidence angle in the range 1–5 degrees from 10 nm thick, nominally [100]-textured MgO films grown on amorphous Si3N4 by IBAD were analyzed by comparing experimental RHEED phi rocking curves with those predicted by the simulation. For some films, an additional 200 nm thermally-grown MgO homoepitaxial layer was grown on top of the IBAD MgO layer. The model enables a quantitative correlation between biaxial texture and RHEED measurements. RHEED results are compared to X-ray rocking curve film analysis.

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