Microstructure Evolution in Nitrogen Implanted Sapphire

2011 ◽  
Vol 275 ◽  
pp. 222-225
Author(s):  
John Kennedy ◽  
Jérôme Leveneur ◽  
Peter P. Murmu ◽  
Andreas Markwitz
Keyword(s):  
Room Temperature ◽  
Normal Incidence ◽  
Nuclear Reaction Analysis ◽  
Average Width ◽  
Force Microscopy ◽  
Ion Concentrations ◽  
Depth Profiles ◽  
Atomic Force ◽  
Nitrogen Ion ◽  
Temperature Dynamic

Low-energy 14N+ ions were implanted with 23 keV under normal incidence into C-axis (0001) sapphire at room temperature. DYNAMIC-TRIM calculations were performed to calculate the N depth profiles for the various fluences from 1x1016 to 1017 cm-2. Electron Beam Annealing (EBA) was performed at a sample temperature of 700 °C for 10 min to allow the implanted and substrate atoms in the implanted layer to move to energetically preferable positions. Nuclear Reaction Analysis revealed the implanted nitrogen ion concentrations. Atomic Force Microscopy and Scanning Electron Microscopy show some nanostructures at the surface of the sapphire substrate exhibiting an average width of 139 ± 25 nm and height of 37 ± 7 nm using the lowest fluence of 1x1016 ions cm-2. Notably for samples implanted with the highest fluence of 1x1017 ions cm-2, bubble/holes like structures appeared after EBA due to out-diffusion of nitrogen that causes blistering and exfoliation effects.

Cryogenic atomic force microscopy

1991 ◽  
Vol 49 ◽  
pp. 54-55
Author(s):  
K. A. Fisher ◽  
M. G. L. Gustafsson ◽  
M. B. Shattuck ◽  
J. Clarke
Keyword(s):  
Room Temperature ◽  
Rapid Freezing ◽  
Cryogenic Temperatures ◽  
Soft Or ◽  
Electrically Conductive ◽  
Force Microscopy ◽  
Flexible Molecules ◽  
Advantages And Disadvantages ◽  
Atomic Force ◽  
Chemical Perturbation

The atomic force microscope (AFM) is capable of imaging electrically conductive and non-conductive surfaces at atomic resolution. When used to image biological samples, however, lateral resolution is often limited to nanometer levels, due primarily to AFM tip/sample interactions. Several approaches to immobilize and stabilize soft or flexible molecules for AFM have been examined, notably, tethering coating, and freezing. Although each approach has its advantages and disadvantages, rapid freezing techniques have the special advantage of avoiding chemical perturbation, and minimizing physical disruption of the sample. Scanning with an AFM at cryogenic temperatures has the potential to image frozen biomolecules at high resolution. We have constructed a force microscope capable of operating immersed in liquid n-pentane and have tested its performance at room temperature with carbon and metal-coated samples, and at 143° K with uncoated ferritin and purple membrane (PM).

The Study on Microstructural and Optical Properties of Nanocrystalline Germanium Films

2010 ◽  
Vol 663-665 ◽  
pp. 324-327
Author(s):  
Chao Song ◽  
Rui Huang
Keyword(s):  
Multilayer Structure ◽  
Room Temperature ◽  
Multilayer Film ◽  
Volume Fraction ◽  
Raman Scattering Spectroscopy ◽  
Force Microscopy ◽  
Room Temperature Photoluminescence ◽  
Atomic Force ◽  
Lower Volume Fraction ◽  
Lower Volume

The germanium film and Ge/Si multilayer structure were fabricated by magnetron sputtering technique on silicon substrate at temperatures of 500°C. Raman scattering spectroscopy measurements reveal that the nanocrystalline Ge occurs in both kinds of samples. Furthermore, from the atomic force microscopy (AFM) results, it is found that the grain size as well as spatially ordering distribution of the nc-Ge can be modulated by the Ge/Si multilayer structure. The room temperature photoluminescence was also observed in the samples. However, compared with that from the nc-Ge film, the intensity of PL from the nc-Ge/a-Si multilayer film becomes weaker, which is attributed to its lower volume fraction of crystallized component.

Hydrogen Transport and Hydrogen-Assisted Cracking in SUS304 Stainless Steel During Deformation at Low Temperatures

2015 ◽  
Author(s):  
Lin Zhang ◽  
Bai An ◽  
Takashi Iijima ◽  
Chris San Marchi ◽  
Brian Somerday
Keyword(s):  
Stainless Steel ◽  
Hydrogen Embrittlement ◽  
Room Temperature ◽  
Hydrogen Release ◽  
Hydrogen Transport ◽  
Force Microscopy ◽  
Atomic Force ◽  
Strain Induced Martensite ◽  
Hydrogen Assisted Cracking ◽  
Slip Planes

The behaviors of hydrogen transport and hydrogen-assisted cracking in hydrogen-precharged SUS304 austenitic stainless steel sheets in a temperature range from 177 to 298 K are investigated by a combined tensile and hydrogen release experiment as well as magnetic force microscopy (MFM) based on atomic force microscopy (AFM). It is observed that the hydrogen embrittlement increases with decreasing temperature, reaches a maximum at around 218 K, and then decreases with further temperature decrease. The hydrogen release rate increases with increasing strain until fracture at room temperature but remains near zero level at and below 218 K except for some small distinct release peaks. The MFM observations reveal that fracture occurs at phase boundaries along slip planes at room temperature and twin boundaries at 218 K. The role of strain-induced martensite in the hydrogen transport and hydrogen embrittlement is discussed.

ATOMIC FORCE MICROSCOPY AND XRD ANALYSIS OF SILVER FILMS DEPOSITED BY THERMAL EVAPORATION

2006 ◽  
Vol 20 (02) ◽  
pp. 217-231 ◽  
Author(s):  
MUHAMMAD MAQBOOL ◽  
TAHIRZEB KHAN
Keyword(s):  
Atomic Force Microscopy ◽  
Grain Size ◽  
Surface Characterization ◽  
Room Temperature ◽  
Thermal Evaporation ◽  
Xrd Analysis ◽  
Force Microscopy ◽  
Atomic Force ◽  
Average Grain Size ◽  
20 Nm

Thin films of pure silver were deposited on glass substrate by thermal evaporation process at room temperature. Surface characterization of the films was performed using X-ray diffraction (XRD) and atomic force microscopy (AFM). Thickness of the films varied between 20 nm and 72.8 nm. XRD analysis provided a sharp peak at 38.75° from silver. These results indicated that the films deposited on glass substrates at room temperature are crystalline. Three-dimension and top view pictures of the films were obtained by AFM to study the grain size and its dependency on various factors. Average grain size increased with the thickness of the deposited films. A minimum grain size of 8 nm was obtained for 20 nm thick films, reaching 41.9 nm when the film size reaches 60 nm. Grain size was calculated from the information provided by the XRD spectrum and averaging method. We could not find any sequential variation in the grain size with the growth rate.

Parameters for Nitrogen Diffusion in Ni, Ti, and Al Obtained from Implanted Bilayers

1992 ◽  
Vol 279 ◽  
Author(s):  
K. K. Bourdelle ◽  
D. O. Boerma
Keyword(s):  
Nuclear Reaction ◽  
Room Temperature ◽  
Vacuum Annealing ◽  
Nitride Layer ◽  
Nuclear Reaction Analysis ◽  
Nitrogen Diffusion ◽  
Depth Profiles ◽  
Solid Interface ◽  
Before And After ◽  
Concentration Depth Profiles

ABSTRACTNi foils and samples consisting of bilayers of Ni or Fe on Al, Ti or Si were implanted at room temperature with 15N+ ions to fluences of around 1×l017 N/cm2. The concentration depth profiles of 15N were determined with nuclear reaction analysis before and after vacuum annealing. It was found that the penetrability for N atoms of the surface and the solid/solid interface plays an important role in the N redistribution during implantation or annealing. The formation of a nitride layer or nitride clusters in Ni and Fe was deduced. Parameters for N migration determined for the metals under investigation are discussed in terms of models.

EFFECT OF ION-ENERGY ON THE PROPERTIES OF AMORPHOUS GaN FILMS PRODUCED BY ION-ASSISTED DEPOSITION

2001 ◽  
Vol 15 (28n29) ◽  
pp. 1355-1360 ◽  
Author(s):  
UDAY LANKE ◽  
ANNETTE KOO ◽  
SIMON GRANVILLE ◽  
JOE TRODAHL ◽  
ANDREAS MARKWITZ ◽  
...  
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Thermal Evaporation ◽  
Ion Beam ◽  
Atomic Ratio ◽  
Nuclear Reaction Analysis ◽  
Ion Energy ◽  
X Ray ◽  
Nitrogen Ions ◽  
Nitrogen Ion

Amorphous GaN films were deposited on various substrates viz. Si (100), quartz, glass, Al, stainless steel and glassy carbon by thermal evaporation of gallium in the presence of energetic nitrogen ions from a Kaufman source. The films were deposited at room temperature and 5 × 10-4 mbar nitrogen partial pressure. The effect of a low energy nitrogen ion beam during the synthesis of films was investigated for energies 40 eV and 90 eV. The N:Ga atomic ratio, bonding state, microstructure, surface morphology, and electrical properties of the deposited a-GaN films were studied by different characterisation techniques. The films are found to be X-ray amorphous in nature, which is confirmed by Raman spectroscopy. Rutherford Backscattering Spectroscopy (RBS) and Nuclear Reaction Analysis (NRA) indicate the N:Ga atomic ratio in the films. The 400-750 eV energy range is thought to be optimal for the production of single-phase amorphous GaN . The effect of ion-energy on optical, Raman, and electrical conductivity measurements of the films is also presented.

Morphology of Silver Thin Films Deposited on TiO2(110) Surfaces

1998 ◽  
Vol 05 (01) ◽  
pp. 387-392 ◽  
Author(s):  
D. Abriou ◽  
D. Gagnot ◽  
J. Jupille ◽  
F. Creuzet
Keyword(s):  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Oxygen Vacancies ◽  
Two Dimensional ◽  
Silver Films ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Silver Deposits ◽  
Silver Thin Films

The growth mode of silver films deposited at room temperature on TiO 2(110) surfaces has been examined by means of atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) in ultrahigh vacuum (UHV) conditions, On clean vacancy-free TiO 2(110) surfaces, 0.1-nm-thick (on average) Ag deposits form a two-dimensional (2D) layer. When the thickness of the silver overlayer is increased, 3D clusters are shown to appear while the 2D film is preserved, furthermore, the influence of surface oxygen vacancies on the growth of Ag/TiO 2(110) is evidenced by well-characterized differences in the morphology of 9-nm-thick silver deposits.

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