Compositional Effects on the Crystallization Kinetics of Nickel Titanium Thin Films

2005 ◽  
Vol 20 (7) ◽  
pp. 1728-1734 ◽  
Author(s):  
Hai Ni ◽  
Hoo-Jeong Lee ◽  
Ainissa G. Ramirez
Keyword(s):  
Thin Films ◽  
Kinetic Parameters ◽  
Nickel Titanium ◽  
Heating And Cooling ◽  
Cooling Conditions ◽  
Transmission Electron ◽  
Titanium Thin Films ◽  
Sputter Deposited ◽  
Kinetics Of

The crystallization and phase transformations of amorphous NiTi thin films were studied using in situ transmission electron microscopy (TEM). These films were sputter-deposited onto micromachined silicon-nitride membranes and subjected to heating and cooling conditions. The microstructural evolution was monitored and recorded. Kinetic parameters such as the nucleation rate, growth rate, and area-fraction transformed were independently determined by noting the number of grains per frame and their change in size. Using the Johnson–Mehl–Avrami–Kolmogorov analysis, fitted kinetic parameters were determined and found to be consistent with TEM observations. To explore the compositional sensitivity of crystallization, samples near-equiatomic and slightly Ti-rich were studied with these methods. TEM micrographs show that equiatomic films exhibit polymorphic crystallization while samples that are slightly off-stoichiometry showed more complicated behavior.

In Situ Rheed and Hrem Study of Initial Stages of Interfacial Reactions of Uhv Deposited Titanium Thin Films on Silicon

1991 ◽  
Vol 222 ◽  
Author(s):  
M. H. Wang ◽  
L. J. Chen
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
High Energy ◽  
Interfacial Reactions ◽  
Silicide Formation ◽  
High Energy Electron ◽  
Transmission Electron ◽  
Titanium Thin Films ◽  
Amorphous Interlayer

ABSTRACTThe initial stages of interfacial reactions of ultrahigh vacuum (UHV) deposited Ti thin films on silicon have been studied by in-situ reflected high energy electron diffraction (RHEED) and transmission electron microscopy (TEM).An amorphous interlayer was found to form during the deposition of the first 1.7-nm-thick Ti layer. In samples annealed at 450 °C for 30–120 min, Ti5Si3, located at the Ti/a-interlayer interface, was identified to be the first nucleated phase. Ti5Si3, Ti5Si4, TiSi and C49-TiSi2 were observed in samples annealed at 475 °C for 30 and 60 min as well as at 500 °C for 10 and 20 min. Fundamental issues in silicide formation are discussed in light of the discovery of the formation of the amorphous interlayer and as many as four different silicide phases in the initial stages of interfacial reactions of UHV deposited Ti thin films on silicon.

Reactions at the Titanium-Silicon Interface Studied Using Hot-Stage Tem

1992 ◽  
Vol 260 ◽  
Author(s):  
Amol Kirtikar ◽  
Robert Sinclair
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Phase Transformations ◽  
Single Crystal Silicon ◽  
Crystal Silicon ◽  
Titanium Thin Films ◽  
Sputter Deposited ◽  
Titanium Silicon ◽  
Silicon Interface

ABSTRACTThe interaction of titanium thin films sputter-deposited onto single crystal silicon was studied by in situ heating experiments within the TEM. Reactions at the Ti-Si interface including amorphization, crystallization, allotropie phase transformations and agglomeration have been observed in real time and recorded on videotape. Interpretation of these recordings can yield a wealth of information on the silicidation process.

Structural and Phase Transformations in Thin Film Ti-Aluminides and Ti/Al Multilayers

1996 ◽  
Vol 434 ◽  
Author(s):  
R. Banerjee ◽  
S. Swaminathan ◽  
R. Wheeler ◽  
H. L. Fraser
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Layer Thickness ◽  
High Resolution Electron Microscopy ◽  
Silicon Substrates ◽  
Two Phase ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Sputter Deposited

AbstractMultilayered Ti/Al thin films (with nominally equal layer thickness of Ti and Al) have been sputter deposited on oxidized silicon substrates at room temperature. Transmission electron microscopy (TEM) and high resolution electron microscopy have been used to characterize the structure of these multilayers as a function of the layer thickness. Ti changed from an hcp to an fcc and back to an hcp structure on reduction of the layer thickness. Al too changed from an fcc to an hcp structure at a layer thickness of 2.5 nm. The observed structural transitions have been explained on the basis of the Redfield-Zangwill model. Subsequently Ti-aluminide thin films were deposited using a γ-TiAl target. These films were found to be amorphous in the as-deposited condition with crystallites of α-Ti(Al) embedded in the amorphous matrix. On annealing under a protective Ar atmosphere at a temperature of 550 °C, the Ti-aluminide film crystallized into a nanocrystalline two phase microstructure consisting of γ-TiAl and α2-Ti3Al. The crystallization of the aluminide film has been investigated in detail by in-situ annealing experiments on a hot stage in the TEM. The results of this investigation have been discussed in this paper.

Kinetics of Copper Grain Growth During Nitridation of Cu-Cr and Cu-Ti Thin Films by In Situ Tem

1994 ◽  
Vol 337 ◽  
Author(s):  
Z. Atzmon ◽  
R. Sharma ◽  
S. W. Russell ◽  
J.W. Mayer
Keyword(s):  
Thin Films ◽  
Growth Stages ◽  
In Situ Tem ◽  
Initial Growth ◽  
Transmission Electron ◽  
Diffusion Controlled ◽  
Cr System ◽  
Rate Limiting ◽  
Kinetics Of

ABSTRACTCo-deposited Cu-Cr and Cu-Ti thin films were heated at various temperatures in an ammonia ambient in an environmental cell placed into the column of a transmission electron microscope (TEM). The reaction dynamics were observed in situ and recorded on a videotape using a TV camera with 1/30 second time resolution. Nitridation of chromium and titanium was accompanied by the nucleation and growth of copper particles starting at 370 and 580°C, respectively. It was found that in the Cu-Ti system at a temperatures regime of 370-400°C the growth rate behaves under a parabolic law; namely, the process is controlled by diffusion of Cu through the nitride matrix. However, for the Cu-Cr system at temperatures of 610-630°C two growth regimes were observed. In the initial growth stages, the surface reaction is rate-limiting, while for longer nitridation times, growth is diffusion-controlled.

Cross-section TEM observations of amorphous nickel-titanium thin films formed by solid state reaction

1990 ◽  
Vol 48 (4) ◽  
pp. 148-149
Author(s):  
Russell E. Cook
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Amorphous Material ◽  
Depth Profiling ◽  
Nickel Titanium ◽  
X Ray Diffraction ◽  
Plan View ◽  
Titanium Thin Films ◽  
Kinetics Of ◽  
Apparent Conflict

There have been conflicting results concerning solid state amorphizing reactions (SSAR) in thin films consisting of alternating multiple layers of nickel and titanium. Clemens first reported evidence for SSAR in Ni-Ti using X-ray diffraction, Auger depth-profiling, and electrical conductivity measurements. The thickness of the Ni and Ti layers was 200 close-packed atom planes each in those samples in which SSAR was observed, although the reaction did not go to completion. Meng, et al. made plan-view TEM observations of films consisting of 10nm layers of Ni and Ti (about 50 atom planes) which had been vacuum- annealed for five hours at 250°C and 300°C. They observed that an intermetallic compound had formed as a result of the anneal, rather than amorphous material. The present study was initiated to explore the apparent conflict and to examine the kinetics of the SSAR if it occurred.

scholarly journals In situ transmission electron microscopy studies of the kinetics of Pt-Mo alloy diffusion in ZrB2 thin films

2013 ◽  
Vol 103 (12) ◽  
pp. 121601 ◽  
Author(s):  
I. Jouanny ◽  
J. Palisaitis ◽  
C. Ngo ◽  
P. H. Mayrhofer ◽  
L. Hultman ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Transmission Electron ◽  
Kinetics Of

In-Situ TEM Observations of Surface Roughening and Defect Formation in Lattice Mismatched Heteroepitaxial Thin Films

1997 ◽  
Vol 505 ◽  
Author(s):  
Cengiz S. Ozkan ◽  
William D. Nix ◽  
Huajian Gao
Keyword(s):  
Thin Films ◽  
Defect Formation ◽  
High Vacuum ◽  
Surface Roughening ◽  
In Situ Tem ◽  
Thick Sample ◽  
Transmission Electron ◽  
Sample Preparation Procedure ◽  
Kinetics Of

ABSTRACTThis paper focuses on in-situ transmission electron microscopy observations of surface roughening and defect formation in heteroepitaxial Sil−xGex thin films. Annealing experiments have been carried out in-situ in the microscope under a high vacuum environment. We comment on the sample preparation procedure for in-situ TEM experiments and explain the importance of having a sufficiently thick sample to have the stress state in the film unaltered. Experimental results of in-situ surface roughening are presented for suberitically and supercritically thick Sil−xGex films. We found that, in a vacuum environment, the kinetics of surface roughening and the resulting surface morphology are much different than in a hydrogen environment.

Application of In Situ HREM to Study Crystallization in Materials

2005 ◽  
Vol 494 ◽  
pp. 7-12
Author(s):  
R. Sinclair ◽  
Kyung Hoon Min ◽  
U. Kwon
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Solid Phase ◽  
Tantalum Oxide ◽  
Nucleation And Growth ◽  
In Situ Observation ◽  
Amorphous Thin Films ◽  
Transmission Electron ◽  
Kinetics Of

A review is given of the application of in situ transmission electron microscopy to study various processes associated with the crystallization of amorphous thin films. Solid phase epitaxial regrowth of ion-implanted silicon is compared with nucleation and growth in deposited thin films. The mechanism of metal-mediated crystallization is deduced directly from high resolution recordings, and the kinetics of tantalum oxide devitrefication are obtained. The advantages of direct in situ observation are described

scholarly journals Nitrogen Effects on Crystallization Kinetics of Amorphous TiOxNy Thin Films

2002 ◽  
Vol 17 (3) ◽  
pp. 550-555 ◽  
Author(s):  
Kyle Hukari ◽  
Rand Dannenberg ◽  
E. A. Stach
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Activation Energy ◽  
Crystallization Behavior ◽  
Index Of Refraction ◽  
Transmission Electron ◽  
Growth Activation ◽  
Diffraction Patterns ◽  
Kinetics Of

The crystallization behavior of amorphous TiOxNy (x ≫ y) thin films was investigated by in situ transmission electron microscopy. The Johnson–Mehl–Avrami–Kozolog (JMAK) theory was used to determine the Avrami exponent, activation energy, and the phase velocity pre-exponent. Addition of nitrogen inhibited diffusion, increasing the nucleation temperature, while decreasing the growth activation energy. Kinetic variables extracted from individual crystallites were compared to JMAK analysis of the fraction transformed, and a change of 6% in the activation energy led to agreement between the methods. From diffraction patterns and index of refraction the crystallized phase was found to be predominantly anatase.

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