Characterization of the Mechanical and Tribological Properties of Sputtered a:SiC Thin Films

1996 ◽  
Vol 436 ◽  
Author(s):  
T. W. Scharf ◽  
R. B. Inturi ◽  
J. A. Barnard

AbstractD.C. magnetron sputtering from a CVD β-SiC target has been utilized to deposit amorphous SiC thin films on various substrates (Coming 7059 glass, unoxidized Si (111), and sapphire). The approximately 1 μm thick films were grown under various Ar sputtering pressures and flow rates. In situ annealing during deposition in vacuum and ex situ post-deposition annealing in air, both at 500°C for two hours, were implemented to determine their effects on the properties of the films. The mechanical properties were assessed via nanoindentation. An accelerated sphere-on-flat(tape) wear tester was administered to measure the wear volume losses and resultant wear rates under 0.1 and 0.2N loads, a 0.024m/s tape speed, and a 1mm ruby sphere diameter. An atomic force microscope (AFM) established the wear scar volume losses as well as the surface arithmetic roughness (RA) and root mean square roughness (RMS) of the films. The amorphous microstructure was verified by X-ray diffractometry. There was a decreasing trend in the plastic contact damage resistance, hardness, elastic modulus, and wear resistance of the films with increased amounts of Ar gas pressure; on the other hand, annealing of the lower Ar content films generated an increase in these properties compared to the as-deposited films. Atomic force microscopy revealed a more pronounced change in surface features and roughness for the in situ annealed films.

2002 ◽  
Vol 17 (7) ◽  
pp. 1622-1633 ◽  
Author(s):  
Xiaowu Fan ◽  
Mi-Kyoung Park ◽  
Chuanjun Xia ◽  
Rigoberto Advincula

Nanostructured montmorillonite/poly(diallyldimethylammonium chloride) multilayer thin films were fabricated up to 100 layers thick by stepwise alternating polyelectrolyte and clay deposition from solution. The structure and morphology of the films were characterized by x-ray diffraction, ellipsometry, atomic force microscopy, and quartz crystal microbalance ex situ and in situ measurements. The mechanical properties were tested by nanoindentation. The hardness of the multilayer thin film was 0.46 GPa. The thin film's modulus was correlated to its ordering and anisotropic structure. Both hardness and modulus of this composite film were higher than those of several other types of polymer thin films.


Author(s):  
K. Barmak

Generally, processing of thin films involves several annealing steps in addition to the deposition step. During the annealing steps, diffusion, transformations and reactions take place. In this paper, examples of the use of TEM and AEM for ex situ and in situ studies of reactions and phase transformations in thin films will be presented.The ex situ studies were carried out on Nb/Al multilayer thin films annealed to different stages of reaction. Figure 1 shows a multilayer with dNb = 383 and dAl = 117 nm annealed at 750°C for 4 hours. As can be seen in the micrograph, there are four phases, Nb/Nb3-xAl/Nb2-xAl/NbAl3, present in the film at this stage of the reaction. The composition of each of the four regions marked 1-4 was obtained by EDX analysis. The absolute concentration in each region could not be determined due to the lack of thickness and geometry parameters that were required to make the necessary absorption and fluorescence corrections.


1999 ◽  
Vol 353 (1-2) ◽  
pp. 194-200 ◽  
Author(s):  
C. Coupeau ◽  
J.F. Naud ◽  
F. Cleymand ◽  
P. Goudeau ◽  
J. Grilhé

2007 ◽  
Vol 1027 ◽  
Author(s):  
Do Young Noh ◽  
Ki-Hyun Ryu ◽  
Hyon Chol Kang

AbstractThe transformation of Au thin films grown on sapphire (0001) substrates into nano crystals during thermal annealing was investigated by in situ synchrotron x-ray scattering and ex situ atomic force microscopy (AFM). By monitoring the Au(111) Bragg reflection and the low Q reflectivity and comparing them with ex situ AFM images, we found that polygonal-shape holes were nucleated and grow initially. As the holes grow larger and contact each other, their boundary turns into Au nano crystals. The Au nano crystals have a well-defined (111) flat top surface and facets in the in-plane direction.


Author(s):  
Pengcheng Chen ◽  
Jordan N. Metz ◽  
Adam S. Gross ◽  
Stuart E. Smith ◽  
Steven P. Rucker ◽  
...  

2009 ◽  
Vol 1239 ◽  
Author(s):  
Yong Sun ◽  
Zaiwang Huang ◽  
Xiaodong Li

AbstractA facile electrophoretic deposition method was successfully applied to achieve novel nanoclay-reinforced polyacrylamide nanocomposite thin films. A special curled architecture of the re-aggregated nanoclay-platelets was identified, providing a possible source for realizing the interlocking mechanism in the nanocomposites. The curled architecture could be the result from strain releasing when the thin films were peeled off from the substrates. Through micro-/nano-indentation and in situ observation of the deformation during tensile test with an atomic force microscope (AFM), the localized deformation mechanism of the synthesized materials was investigated in further details. The results implied that a localized crack diversion mechanism worked in the synthesized nanocomposite thin films, which resembled its nature counterpart-nacre. The deformation behavior and fracture mechanism were discussed with reference to lamellar structure, interfacial strength between the nanoclays and the polyacrylamide matrix, and nanoclay agglomeration.


2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Henning Fouckhardt ◽  
Johannes Strassner ◽  
Thomas H. Loeber ◽  
Christoph Doering

III/V semiconductor quantum dots (QD) are in the focus of optoelectronics research for about 25 years now. Most of the work has been done on InAs QD on GaAs substrate. But, e.g., Ga(As)Sb (antimonide) QD on GaAs substrate/buffer have also gained attention for the last 12 years. There is a scientific dispute on whether there is a wetting layer before antimonide QD formation, as commonly expected for Stransky-Krastanov growth, or not. Usually ex situ photoluminescence (PL) and atomic force microscope (AFM) measurements are performed to resolve similar issues. In this contribution, we show that reflectance anisotropy/difference spectroscopy (RAS/RDS) can be used for the same purpose as an in situ, real-time monitoring technique. It can be employed not only to identify QD growth via a distinct RAS spectrum, but also to get information on the existence of a wetting layer and its thickness. The data suggest that for antimonide QD growth the wetting layer has a thickness of 1 ML (one monolayer) only.


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