Structural Transitions in Titanium-Aluminum Thin Film Multilayers

1993 ◽  
Vol 317 ◽  
Author(s):  
Rajiv Ahuja ◽  
Hamish L. Fraser
Keyword(s):  
Thin Film ◽  
Structural Transitions ◽  
Composition Modulation ◽  
Aluminum Thin Film ◽  
Transmission Electron ◽  
Titanium Aluminum ◽  
High Resolution Tem ◽  
Film Microstructure ◽  
The Stability ◽  
Modulation Wavelength

ABSTRACTThis paper presents the results of a detailed study of titanium - aluminum thin film multilayers fabricated using UHV Magnetron sputtering. Transmission electron Microscopy (TEM) techniques have been used to characterize the structure of these multilayers and to study the various structural transitions as a function of the composition modulation wavelength (CMW). Evidence is presented which indicates the existence of a titanium based fcc structure in these films, below a critical CMW. At even smaller values of CMW, both the Ti and Al layers adopt the hep structure and are coherent with each other. The evolution of thin film microstructure has been studied using high resolution TEM (HRTEM) and an attempt is made to rationalize the stability of different phases based on the energetics of atomic stacking.

Face-centered-cubic titanium: An artifact in titanium/aluminum multilayers

1999 ◽  
Vol 14 (5) ◽  
pp. 1977-1981 ◽  
Author(s):  
J. Bonevich ◽  
D. van Heerden ◽  
D. Josell
Keyword(s):  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Reflection And Transmission ◽  
Multilayer Systems ◽  
Composition Modulation ◽  
Transmission Electron ◽  
Titanium Aluminum ◽  
High Resolution Tem ◽  
Face Centered

The present investigation is the first comprehensive comparative study of x-ray diffraction (XRD) and transmission electron microscopy (TEM) results to address the important issue of fcc Ti formation in nanoscale multilayers. Ti/Al multilayers with 7.2 and 5.2 nm composition modulation wavelengths were studied by reflection and transmission XRD as well as transmission electron diffraction (ED), high-resolution TEM, and energy-filtered TEM. Previous reports have claimed deposition of fcc Ti in multilayer systems. Our results demonstrate that the Ti in Ti/Al multilayers deposits in the hcp form and that fcc Ti is merely an artifact of producing specimens for cross-sectional TEM.

TEM Analysis of Long-Period Polytypes in SiC—S

1976 ◽  
Vol 34 ◽  
pp. 630-631
Author(s):  
S. Shinozaki ◽  
J. W. Sprys
Keyword(s):  
Electron Diffraction ◽  
Isothermal Annealing ◽  
Tem Analysis ◽  
Long Period ◽  
Transmission Electron ◽  
Average Grain Size ◽  
High Resolution Tem ◽  
Structural Lattice ◽  
The Stability ◽  
Continuous Curves

In reaction sintered SiC (∽ 5um average grain size), about 15% of the grains were found to have long-period structures, which were identifiable by transmission electron microscopy (TEM). In order to investigate the stability of the long-period polytypes at high temperature, crystal structures as well as microstructural changes in the long-period polytypes were analyzed as a function of time in isothermal annealing.Each polytype was analyzed by two methods: (1) Electron diffraction, and (2) Electron micrograph analysis. Fig. 1 shows microdensitometer traces of ED patterns (continuous curves) and calculated intensities (vertical lines) along 10.l row for 6H and 84R (Ramsdell notation). Intensity distributions were calculated based on the Zhdanov notation of (33) for 6H and [ (33)3 (32)2 ]3 for 84R. Because of the dynamical effect in electron diffraction, the observed intensities do not exactly coincide with those intensities obtained by structure factor calculations. Fig. 2 shows the high resolution TEM micrographs, where the striped patterns correspond to direct resolution of the structural lattice periodicities of 6H and 84R structures and the spacings shown in the figures are as expected for those structures.

The Oxidation Stability of Boron Nitride Thin Films on MgO and TiO2 Substrates

1991 ◽  
Vol 250 ◽  
Author(s):  
Xiaomei Qiu ◽  
Abhaya K. Datye ◽  
Robert T. Paine ◽  
Lawrence. F. Allard
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Oxidation Stability ◽  
Film Coating ◽  
Thin Film Coating ◽  
Film Coatings ◽  
Thin Film Coatings ◽  
Transmission Electron ◽  
The Stability

AbstractThe stability of BN thin film coatings (2–5 nm thick) on MgO and TiO2 substrates was investigated using transmission electron microscopy (TEM). The samples were heated in air for at least 16 hours at temperatures ranging from 773 K - 1273 K. On MgO supports, the BN thin film coating was lost by 1073 K due to a solid state reaction with the substrate leading to formation of Mg2B2O5. No such reaction occurred with the TiO2 substrate and the BN was stable even at 1273 K. However, the coating appeared to ball up and phase segregate into islands of near-graphitic BN and clumps of TiO2 (rutile). The oxidizing treatment appears to promote the transformation from turbostratic BN to graphitic BN.

Structure of composition-modulated Cu/Ni thin films prepared by electrodeposition

1989 ◽  
Vol 4 (4) ◽  
pp. 755-758 ◽  
Author(s):  
J. Yahalom ◽  
D. F. Tessier ◽  
R. S. Timsit ◽  
A. M. Rosenfeld ◽  
D. F. Mitchell ◽  
...  
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Cross Section ◽  
Film Structure ◽  
Composition Modulation ◽  
Transmission Electron ◽  
Electron Energy Loss ◽  
Multilayered Thin Films

Copper/nickel multilayered thin-films prepared by electrodeposition have been examined in cross section by electron energy loss spectroscopy and high-resolution transmission electron microscopy. The results of the examinations provide the first direct experimental evidence of the large composition modulation across successive layers in the thin-film structure and the coherent nature of Cu/Ni interfaces.

Substrate Surface Dependence of the Microstructure of μc-Si,Ge:H Deposited by Reactive Magnetron Sputtering (RMS)

1995 ◽  
Vol 405 ◽  
Author(s):  
S. M. Cho ◽  
K. Christensen ◽  
D. Wolfe ◽  
H. Ying ◽  
D. R. Lee ◽  
...  
Keyword(s):  
Thin Film ◽  
Magnetron Sputtering ◽  
Substrate Surface ◽  
Reactive Magnetron Sputtering ◽  
Reactive Magnetron ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Film Microstructure ◽  
Substrate Surfaces

AbstractWe have investigated on the effect of different substrate surfaces in changing the microstructure of μc-SixGe1-x:H films prepared by reactive magnetron sputtering. Films were deposited on hydrogen terminated Si(111), Si(100) surfaces, and surfaces chemical and plasma oxides. The thin film microstructure was characterized by Fourier transform infrared spectroscopy (FTIR), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and Raman scattering.

Structure and Mechanical Properties of Fe/Zr Multilayers.

1991 ◽  
Vol 239 ◽  
Author(s):  
Joost J. Vlassak ◽  
Takenori Nakayama ◽  
Toyohiko J. Konno ◽  
William D. Nix
Keyword(s):  
Elastic Modulus ◽  
Multilayer Films ◽  
Sputter Deposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Composition Modulation ◽  
Average Value ◽  
Transmission Electron ◽  
Continuous Indentation ◽  
Modulation Wavelength

ABSTRACTIron zirconium multilayer films have been prepared by sputter deposition and studied using x-ray diffraction, high-resolution transmission electron microscopy and Nanoindenter techniques. The composition-modulation wavelength was varied between 0.8 and 92 nm. For modulation wavelengths greater than 4 nm the multilayers are crystalline with amorphous interfaces; for smaller wavelengths the samples are entirely amorphous. It was not possible to obtain layered structures with wavelengths smaller than 0.8 nm.Both the hardness and the elastic modulus were measured as a function of composition-modulation wavelength by means of continuous indentation testing. The elastic modulus shows some variation with wavelength; the average value being 131 GPa. The hardness increases sharply when the modulation wavelength decreases below 4 nm. We attribute this increase to die crystalline to amorphous transition that occurs in these films at this wavelength.

Stability and Oxidation Behavior of Ir Thin Film Electrodes on Si and SiO2

1998 ◽  
Vol 541 ◽  
Author(s):  
K.L. Saenger ◽  
A. Grill ◽  
T.M. Shaw ◽  
D.A. Neumayer ◽  
Chenting Lin ◽  
...  
Keyword(s):  
Thin Film ◽  
Oxidation Behavior ◽  
Layer Structure ◽  
Areal Density ◽  
Factors Affecting ◽  
Transmission Electron ◽  
Thin Film Electrodes ◽  
The Stability ◽  
20 Nm

AbstractThis paper examines factors affecting the oxidation behavior of Ir thin film electrodes and the stability of bilayer Ir/Ir-Ir-O-Si electrodes on silicon substrates. We first examine the morphology and texture of faceted IrO2 extrusions formed on the Ir films during thermal oxidation, and show that an Ir grain-growth anneal in N2 at 650°C for 5 min prior to the oxidation treatment increases both the areal density of IrO2 extrusions and the IrO2<110> x-ray diffraction intensity while decreasing apparent film roughness. We then examine the stability of bilayer lr(100 nm)/Ir(20 nm) films on polycrystalline silicon and show how fairly mild oxygen anneals of the Ir(20 nm)/Si structures can provide an in-situ formed Ir-O-Si barrier that protects the subsequently deposited Ir(100 nm) layer from silicidation reactions during annealing in N2 ambients at 750°C. Transmission electron microscopy indicates that this in-situ formed barrier at the Ir/Si interface has a two layer structure comprising an IrSix underlayer in contact with the silicon substrate and an SiO2 overlayer directly below the remaining Ir.

Microstructural transitions in Titanium-Aluminum thin film multilayers

1994 ◽  
Vol 23 (10) ◽  
pp. 1027-1034 ◽  
Author(s):  
Rajiv Ahuja ◽  
Hamish L. Fraser
Keyword(s):  
Thin Film ◽  
Aluminum Thin Film ◽  
Titanium Aluminum

Transmission Electron Microscopy of oriented Co84Cr14Ta2 thin films for longitudinal magnetic recording

1991 ◽  
Vol 49 ◽  
pp. 756-757
Author(s):  
T. P. Nolan
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Cost ◽  
Low Noise ◽  
Information Storage ◽  
High Coercivity ◽  
Magnetic Alloy ◽  
Magnetic Media ◽  
Transmission Electron

Thin film magnetic media are being used as low cost, high density forms of information storage. The development of this technology requires the study, at the sub-micron level, of morphological, crystallographic, and magnetic properties, throughout the depth of the deposited films. As the microstructure becomes increasingly fine, widi grain sizes approaching 100Å, the unique characterization capabilities of transmission electron microscopy (TEM) have become indispensable to the analysis of such thin film magnetic media.Films were deposited at 225°C, on two NiP plated Al substrates, one polished, and one circumferentially textured with a mean roughness of 55Å. Three layers, a 750Å chromium underlayer, a 600Å layer of magnetic alloy of composition Co84Cr14Ta2, and a 300Å amorphous carbon overcoat were then sputter deposited using a dc magnetron system at a power of 1kW, in a chamber evacuated below 10-6 torr and filled to 12μm Ar pressure. The textured medium is presently used in industry owing to its high coercivity, Hc, and relatively low noise. One important feature is that the coercivity in the circumferential read/write direction is significandy higher than that in the radial direction.

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