(111) Monocrystalline Nickel Films

Author(s):  
T.E. Pratt ◽  
R.W. Vook

(111) oriented thin monocrystalline Ni films have been prepared by vacuum evaporation and examined by transmission electron microscopy and electron diffraction. In high vacuum, at room temperature, a layer of NaCl was first evaporated onto a freshly air-cleaved muscovite substrate clamped to a copper block with attached heater and thermocouple. Then, at various substrate temperatures, with other parameters held within a narrow range, Ni was evaporated from a tungsten filament. It had been shown previously that similar procedures would yield monocrystalline films of CU, Ag, and Au.For the films examined with respect to temperature dependent effects, typical deposition parameters were: Ni film thickness, 500-800 A; Ni deposition rate, 10 A/sec.; residual pressure, 10-6 torr; NaCl film thickness, 250 A; and NaCl deposition rate, 10 A/sec. Some additional evaporations involved higher deposition rates and lower film thicknesses.Monocrystalline films were obtained with substrate temperatures above 500° C. Below 450° C, the films were polycrystalline with a strong (111) preferred orientation.

1992 ◽  
Vol 242 ◽  
Author(s):  
W. J. Meng ◽  
T. A. Perry ◽  
J. Heremans ◽  
Y. T. Cheng

ABSTRACTThin films of aluminum nitride were grown epitaxially on Si(111) by ultra-high-vacuum dc magnetron reactive sputter deposition. Epitaxy was achieved at substrate temperatures of 600° C or above. We report results of film characterization by x-ray diffraction, transmission electron microscopy, and Raman scattering.


2000 ◽  
Vol 650 ◽  
Author(s):  
A. Meldrum ◽  
K. Beaty ◽  
L. A. Boatner ◽  
C. W. White

ABSTRACTIrradiation-induced amorphization of Cd2Nb2O7 pyrochlore was investigated by means of in-situ temperature-dependent ion-irradiation experiments in a transmission electron microscope, combined with ex-situ ion-implantation (at ambient temperature) and RBS/channeling analysis. The in-situ experiments were performed using Ne or Xe ions with energies of 280 and 1200 keV, respectively. For the bulk implantation experiments, the incident ion energies were 70 keV (Ne+) and 320 keV (Xe2+). The critical amorphization temperature for Cd2Nb2O7 is ∼480 K (280 keV Ne+) or ∼620 K (1200 keV Xe2+). The dose for in-situ amorphization at room temperature is 0.22 dpa for Xe2+, but is 0.65 dpa for Ne+ irradiation. Both types of experiments suggest a cascade overlap mechanism of amorphization. The results were analyzed in light of available models for the crystalline-to-amorphous transformation and were compared to previous ionirradiation experiments on other pyrochlore compositions.


1990 ◽  
Vol 192 ◽  
Author(s):  
Yoshihiro Hishikawa ◽  
Sadaji Tsuge ◽  
Noboru Nakamura ◽  
Shinya Tsuda ◽  
Shoichi Nakano ◽  
...  

ABSTRACTWide-gap a-Si:H films with device quality (Tauc’s optical gap > 1.9eV, σph under AMI.5, 100mW/cm2 illumination ≥ 10−5, Ω−1cm−1, a σph/σ a≥106) have been fabricated. These films are deposited at low substrtate temperatures (TS≤80°C ) either by diluting SiH4 with H2 or optimizing the plasma parameters in a capacitively–coupled RF plasma–CVD reactor. Reduction in the SiH2 bond density and the ESR spin density are also observed. In this study, good film quality is always accompanied by a small deposition rate. Furthermore, σph is nearly the same if the deposition rate and Ts is the same, regardless of other deposition parameters. This suggests that the surface reactions or structural relaxations at the film-growing surface can produce high–quality a–Si:H films even at low TsS, if the deposition rate is low. Results in thermal annealing, light exposure, and solar cell performance confirm that these films have device quality and wide bandgap.


1990 ◽  
Vol 198 ◽  
Author(s):  
R. D. Bringans ◽  
D. K. Biegelsen ◽  
F. A. Ponce ◽  
L.-E. Swartz ◽  
J. C. Tramontana

ABSTRACTZinc selenide films have been grown heteroepitaxially on Si(100) substrates by molecular beam epitaxy. The growth has been carried out for raised substrate temperatures and also at room temperature followed by solid-phase epitaxial (SPE) regrowth. The ZnSe films have been characterized by a number of surface-sensitive techniques and both the interface and the bulk material have been examined with high resolution transmission electron microscopy (HRTEM). We find that an interlayer, which is most likely SiSex, is present between the ZnSe film and the Si substrate for growths made at 300 °C and causes loss of epitaxy. In the case of room temperature deposition and SPE, it is absent, leading to good epitaxy. In the latter situation, the films are very uniform and there is a 4° rotation of the ZnSe crystal axes relative to those of the Si substrate.


1995 ◽  
Vol 397 ◽  
Author(s):  
D.L. Kjendal ◽  
Ashok Kumar ◽  
R.B. Inturi ◽  
J. A. Barnard

ABSTRACTThin films of poly(tetrafluoroethylene) have been deposited on amorphous (7059 Corning Glass) and silicon(l00) substrates at various temperatures by the Pulsed Laser Deposition technique. The deposition was carried out at high vacuum (˜10-6 torr)at temperatures ranging from room temperature to 350°C. The mechanical properties of these films at the varying process temperatures have been evaluated by nano-indentation techniques and compositional properties of the films have been characterized by Fourier Transform Infrared spectroscopy. The deposition parameters have been optimized in order to produce good quality films.


1991 ◽  
Vol 6 (10) ◽  
pp. 2019-2021 ◽  
Author(s):  
S.R. Harris ◽  
D.H. Pearson ◽  
C.M. Garland ◽  
B. Fultz

Films of chemically disordered fcc Ni3Al were synthesized by the vacuum evaporation of Ni3Al onto room temperature and liquid nitrogen temperature substrates. X-ray diffractometry and transmission electron microscopy showed the material to be single phase with an average grain size of about 4 nm. The formation of the equilibrium L12 ordered phase occurred simultaneously with grain growth at temperatures above 350°C. Differential scanning calorimetry provided ordering enthalpies of 7 kJ/mole and 9 kJ/mole for material evaporated onto room temperature and liquid nitrogen temperature substrates, respectively.


2017 ◽  
Vol 28 (1) ◽  
pp. 149
Author(s):  
Baha'a A. Al-Hilli

The objective of this study is to assess the influence of nano-particle Fe2O3 thin film thickness on some physical properties which were prepared by magnetron DC- sputtering on glass substrate at room temperature. The structure was tested with X-Ray diffraction and it was to be amorphous and to become single crystal with recognized peak in (003) after annealing at temperature 500oC. The physical properties as a function of deposition parameters and then film thickness were studied. The optical properties such as absorbance, energy gap and some optical constants are measured and found that of about (3eV) energy gap.


Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 535 ◽  
Author(s):  
María-Dolores Avilés ◽  
Ramón Pamies ◽  
José Sanes ◽  
María-Dolores Bermúdez

Graphene (0.5 wt.%) was dispersed in the hydrophobic room-temperature ionic liquid 1-octyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide (IL) to obtain a new non-Newtonian (IL + G) nanolubricant. Thin layers of IL and (IL + G) lubricants were deposited on stainless steel disks by spin coating. The tribological performance of the new thin layers was compared with those of full fluid lubricants. Friction coefficients for neat IL were independent of lubricant film thickness. In contrast, for (IL + G) the reduction of film thickness not only afforded 40% reduction of the friction coefficient, but also prevented wear and surface damage. Results of surface profilometry, scanning and transmission electron microscopy (SEM and TEM), energy dispersive analysis (EDX), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy were discussed.


2012 ◽  
Vol 717-720 ◽  
pp. 845-848 ◽  
Author(s):  
Alexia Drevin-Bazin ◽  
Jean François Barbot ◽  
Thierry Cabioc’h ◽  
Marie France Beaufort

In this study, investigations on MAX phase Ti3SiC2 formation to n-type 4H-SiC substrates and its ohmic-behaved are reported. Ti-Al layers were deposited onto SiC substrates at room temperature by magnetron sputtering in high vacuum system. Thermal annealing at 1000°C in Ar atmosphere were performed to allow interdiffusion processes. X-ray diffraction and High Resolution Transmission Electron Microscopy reveal that a Ti3SiC2 contact, in perfect epitaxy with 4H-SiC substrate, is so-obtained. In situ annealing experiment underlines the evolution of Ti-Al contact microstructure versus temperature. The evolution of contact system from Schottky to Ohmic behaved is observed by I-V measurements for annealing temperatures larger than 700°C.


2010 ◽  
Vol 121-122 ◽  
pp. 52-57
Author(s):  
Shih Wei Mao ◽  
Jung Hsiung Shen ◽  
Der Shin Gan ◽  
Hsing Lu Huang ◽  
Sung Wei Yeh

Temperature dependent oriented growth of ZnO thin film deposited on NaCl (001) substrates using ion beam sputtering was studied by transmission electron microscopy (TEM). Thin films showing a texture due to parallel epitaxy with NaCl (001) as deposited at 100 oC, whereas thin films deposited at 400 oC can form a texture. The microstructure and the epitaxial relationship with the NaCl (001) plane were studied by a high-resolution TEM. The possible causes for the orientation changed with temperature are discussed. The optical transparency of the nanofilms grown from room temperature to 400 oC was measured.


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