Short-range order in amorphous co-sputtered Ta-Al thin films

1986 ◽  
Vol 44 ◽  
pp. 860-861
Author(s):  
J.C. Barry ◽  
R.S. Timsit ◽  
D. Landheer
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Microscope ◽  
High Resolution ◽  
Short Range ◽  
Short Range Order ◽  
Range Order ◽  
Transmission Electron ◽  
Thin Film Resistors ◽  
Diffraction Patterns

Tantalum-aluminium thin films have assumed considerable technological importance since the discovery in the late 1960's that the films are useful in the fabrication of thin film resistors and capacitors. It is generally claimed that these films, when prepared by co-sputtering Ta and Al, are amorphous over a range of Ta concentrations extending approximately from 15 to 75 at%, and are crystalline beyond this range. Diffuse electron diffraction patterns and ‘mottle pattern’ transmission electron micrographs are typical characteristics of the amorphous phase. In this present study we have attempted to identify any atomic short range order in the amorphous Ta-Al films and to follow the changes in this order as the Ta concentration increases across the amorphous/crystalline transition. The co-sputtered Ta-Al films of ≈100A thickness were examined in a high resolution 4000EX electron microscope (top entry, ±15°(x,y) tilt, Cs = 1.0mm ) at 400kV.

High-Resolution Transmission Electron Microscope Analysis of Tungsten Carbide Thin Films

1998 ◽  
Vol 520 ◽  
Author(s):  
Wentao Qin ◽  
W. Shih ◽  
J. Lib ◽  
W. James ◽  
H. Siriwardaneane ◽  
...  
Keyword(s):  
Thin Films ◽  
Electron Microscope ◽  
High Resolution ◽  
Tungsten Carbide ◽  
Transmission Electron Microscope ◽  
Chemical Vapor ◽  
Unit Cell Size ◽  
Aspect Ratios ◽  
Transmission Electron ◽  
Diffraction Patterns

ABSTRACTElectron diffraction patterns and high-resolution transmission electron microscope (HREM) images show that the dominant phase in tungsten carbide thin films grown by plasma enhanced chemical vapor deposition is WC(1−x). The f.c.c crystal structure and the unit cell size of WC(1−x) have been determined via electron powder diffraction. The two largest and most dominant spacings in HREM images are the {111} and {002} spacings of WC(1−x). Cross lattice fringes along the two most densely populated zones of WC(1−x) are seen. The sizes and aspect ratios of nano-crystals have been measured from HREM images. Stereo analysis of individual nano-crystals has been done. Confirmation of the 3-D structure of WC(1−x) via spacings larger than 0.15 nm will require a tilt larger than 35° between images.

Short-Range Order and Nanocrystallization in Amorphous Zr-Ti-Cu-Ni-Al

1999 ◽  
Vol 580 ◽  
Author(s):  
L. Q. Xing ◽  
Xiaofeng Gu ◽  
T. A. Lusby ◽  
A. J. Melmed ◽  
T. C. Hufnagel
Keyword(s):  
Amorphous Alloys ◽  
Short Range ◽  
Short Range Order ◽  
Structural Changes ◽  
Range Order ◽  
Transmission Electron ◽  
Microscope Images ◽  
Diffraction Patterns ◽  
Kinetics Of ◽  
Ti Content

AbstractWe have examined the effect of Ti content on the crystallization kinetics of Zr-based amorphous alloys. In Zr59Ti3Cu20Ni8Al10, annealing above the glass transition temperature produces 50-100 nm crystalline precipitates, as seen in transmission electron microscope images. In contrast, TEM images and diffraction patterns from annealed Zr54.5Ti7.5Cu20Ni8Al10 show no evidence of crystalline phase formation. Structural changes upon annealing do occur in this alloy, however, as revealed by field ion microscopy. The effect of Ti is to favor the formation of clusters of short-range order; this tendency for clustering is apparently the cause of difference in crystallization behavior between the two alloys.

Ordering in Ni4Mo by TEM and APFIM

1987 ◽  
Vol 45 ◽  
pp. 214-215
Author(s):  
E.A. Kenik ◽  
T.A. Zagula ◽  
M.K. Miller ◽  
J. Bentley
Keyword(s):  
Electron Irradiation ◽  
Low Temperatures ◽  
Short Range ◽  
Atom Probe ◽  
Range Order ◽  
Considerable Time ◽  
Probe Field ◽  
Disordered Phase ◽  
Transmission Electron ◽  
Diffraction Patterns

The state of long-range order (LRO) and short-range order (SRO) in Ni4Mo has been a topic of interest for a considerable time (see Brooks et al.). The SRO is often referred to as 1½0 order from the apparent position of the diffuse maxima in diffraction patterns, which differs from the positions of the LRO (D1a) structure. Various studies have shown that a fully disordered state cannot be retained by quenching, as the atomic arrangements responsible for the 1½0 maxima are present at temperatures above the critical ordering temperature for LRO. Over 20 studies have attempted to identify the atomic arrangements associated with this state of order. A variety of models have been proposed, but no consensus has been reached. It has also been shown that 1 MeV electron irradiation at low temperatures (∼100 K) can produce the disordered phase in Ni4Mo. Transmission electron microscopy (TEM), atom probe field ion microscopy (APFIM), and electron irradiation disordering have been applied in the current study to further the understanding of the ordering processes in Ni4Mo.

New phases and chemical short range order in co-deposited CoFe thin films with bcc structure: an NMR study

1997 ◽  
Vol 103 (1) ◽  
pp. 5-12 ◽  
Author(s):  
M. Wojcik ◽  
J.P. Jay ◽  
P. Panissod ◽  
E. Jedryka ◽  
J. Dekoster ◽  
...  
Keyword(s):  
Thin Films ◽  
Short Range ◽  
Short Range Order ◽  
Range Order ◽  
Nmr Study ◽  
Bcc Structure

On `non-stoichiometric phases' in thin films of rare-earth oxides

1978 ◽  
Vol 34 (6) ◽  
pp. 1025-1027 ◽  
Author(s):  
M. Gasgnier ◽  
P. Caro
Keyword(s):  
Thin Films ◽  
Rare Earth ◽  
Long Range ◽  
Short Range ◽  
Short Range Order ◽  
Rare Earth Oxides ◽  
Range Order ◽  
Acta Cryst ◽  
The Rare Earth

Kaul & Saxena [Acta Cryst. (1977), A33, 992-996] have reported the existence of long-range and short-range order in a non-stoichiometric phase 'LnO x ' (Ln = rare earth). It is shown that the experiments they are describing are indeed the oxidation of the rare-earth hydride LnH2 into the rare-earth cubic C-type sesquioxide. The interpretation they give of their experiments is to be discarded entirely.

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