An attempt to observe phonon dimensionality crossover effects in the inelastic scattering rate of thin free-standing aluminum films

1992 ◽  
Vol 88 (3-4) ◽  
pp. 261-272 ◽  
Author(s):  
Y. K. Kwong ◽  
K. Lin ◽  
M. S. Isaacson ◽  
J. M. Parpia
Keyword(s):  
Inelastic Scattering ◽  
Free Standing ◽  
Aluminum Films ◽  
Scattering Rate ◽  
Crossover Effects

The Effect of Adsorbeb Oxygen Ions on the Inelastic Scattering of Photo-Electrons at the Metal-Vacuum Interface

1984 ◽  
Vol 41 ◽  
Author(s):  
W. Pong ◽  
D. Brandt ◽  
Z. X. He ◽  
W. Imaino
Keyword(s):  
Inelastic Scattering ◽  
Energy Levels ◽  
Film Deposition ◽  
Photoelectron Spectra ◽  
Aluminum Films ◽  
Vacuum Level ◽  
Oxygen Ions ◽  
Resonant States ◽  
Initial Stage ◽  
Vacuum Interface

AbstractMeasurements of uv photoemission from evaporated aluminum films were made at photon energies 7.7–11 eV as a function of time after film deposition. Evidence of the initial stage of chemisorption of oxygen can be seen in the uv photoelectron spectra. The spectra taken immediately after film deposition showed a smooth energy distribution characteristic of clean aluminum. Structure in the spectra was found to appear at approximately 60 minutes after deposition at 10−9 Torr. Three noticeable features were observed at 1.0, 1.3, and 2.5 eV above the vacuum level. They appeared stationary with increasing photon energy. The structure can be attributed to inelastic scattering of photoelectrons into resonant states associated with oxygen ions on the metal surface. The energy levels of the calculated resonant states of a helium-like system are compared with the energy of the observed structure. The agreement suggests that there are adsorbed 0− ions to which photoelectrons can be scattered at the metal-vacuum interface.

Optimization of mechanical properties of thin free-standing metal films for RF-MEMS

2004 ◽  
Vol 820 ◽  
Author(s):  
Jaap M.J. den Toonder ◽  
Auke R. van Dijken
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Yield Strength ◽  
Rf Mems ◽  
High Yield ◽  
Film Material ◽  
X Ray Diffraction ◽  
Free Standing ◽  
Aluminum Films ◽  
Materials Used

AbstractThe mechanical properties of the thin film materials used in RF-MEMS are crucial for the reliability and proper functioning of the devices. In this paper we study a large number of aluminum alloys as possible RF-MEMS thin film materials. The yield strength and creep properties are measured using nano-indentation. The results show that the mechanical properties of thin aluminum films can be improved substantially by alloying elements. Of the alloys studied in this paper, AlCuMgMn in particular seems quite promising as a thin film material for RF MEMS, having both high yield strength and little creep. Using X-ray diffraction and electron microscopy, the observed effects are partly explained.

Film Thickness Effect on Tensile Properties and Microstructures of Submicron Aluminum Thin Films on Polyimide

1996 ◽  
Vol 436 ◽  
Author(s):  
Y. S. Kang ◽  
P. S. Ho ◽  
R. Knipe ◽  
J. Tregilgas
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Film Thickness ◽  
Metal Film ◽  
Tensile Force ◽  
Thickness Effect ◽  
Published Data ◽  
Free Standing ◽  
Aluminum Films ◽  
Flexible Polymer

AbstractThe mechanical behavior of the metal film on a polymer substrate becomes an important issue in microelectronics metallization. The metal/polymer structure is also useful to investigate the deformation behavior of very thin free-standing metal film since the flexible polymer serves as a deformable substrate. The tensile force-elongation curves have been measured using a microtensile tester for aluminum thin films, deposited on a PMDA-ODA polyimide film, in the thickness range from 60 rum to 480 nm. The stress-strain curves for aluminum films were constructed by subtracting these curves with polyimide curves measured separately. Tensile strength increases linearly with decreasing film thickness from 196 MPa to 408 MPa within the film thickness range studied. This is in good agreement with the published data for free-standing aluminum films in the same thickness range. The measured Young's modulus is lower than the bulk modulus and exhibits no systematic dependence on the film thickness. The microstructures of aluminum films have been examined using a transmission electron microscope (TEM). These films posses the (111)-textured columnar grain structures. Grain sizes exhibit log-normal distributions and the mean grain size increases monotonically with the film thickness. An attempt is made to evaluate the effect of film thickness and grain size on the strength of aluminum thin film and the result is discussed.

ANOMALOUS TEMPERATURE EFFECT ON POINT-CONTACT Ag–LaBa2Cu3O7-x CONDUCTANCE SPECTRA

2000 ◽  
Vol 14 (22n23) ◽  
pp. 819-825 ◽  
Author(s):  
E. HATTA ◽  
V. M. SVISTUNOV ◽  
Yu. F. REVENKO ◽  
M. A. BELOGOLOVSKII ◽  
N. A. DOROSHENKO ◽  
...  
Keyword(s):  
Inelastic Scattering ◽  
Point Contact ◽  
Proximity Effects ◽  
Charge Carriers ◽  
Differential Conductance ◽  
Anomalous Temperature ◽  
Bulk Ceramic ◽  
Scattering Rate ◽  
Wide Range ◽  
Superconducting Parameters

The observation of an anomalous temperature behavior of the differential conductance versus voltage curves in contacts formed by an Ag tip and a bulk ceramic LaBa2Cu3O7-x with Tc around 92 K is reported. For a wide range of temperatures from Tc to helium-liquid ones, we have found a crossover from curves typical for a pure conducting normal metal–superconductor interface up to Giaever tunneling characteristics with gap features shifted to high biases. We take into account the existence of a degraded interlayer with suppressed superconducting parameters between a normal injector and a superconducting bulk and interpret qualitatively the data in terms of mesoscopic proximity effects. We argue that as the temperature is decreased, (i) the electron localization in a disordered region is enhanced, and (ii) in the interlayer, inelastic scattering processes become more effective. The latter was considered as a result of the inelastic scattering rate changes for charge carriers interacting with magnetic excitations in the near-interface region of high-Tc compound junctions.

Enhancement of elastic and inelastic scattering lengths in quasi-free-standing graphene measured with contactless microwave spectroscopy

2013 ◽  
Vol 88 (16) ◽  
Author(s):  
Aneta Drabińska ◽  
Maria Kamińska ◽  
Agnieszka Wołoś ◽  
Włodek Strupinski ◽  
Andrzej Wysmołek ◽  
...  
Keyword(s):  
Inelastic Scattering ◽  
Microwave Spectroscopy ◽  
Free Standing ◽  
Elastic And Inelastic Scattering ◽  
Scattering Lengths

scholarly journals INTRINSIC PHASE-DECOHERENCE OF ELECTRONS BY TWO-LEVEL SYSTEMS

2002 ◽  
Vol 16 (14) ◽  
pp. 511-517 ◽  
Author(s):  
VIPIN SRIVASTAVA ◽  
RAISHMA KRISHNAN
Keyword(s):  
Phase Shift ◽  
Inelastic Scattering ◽  
Low Temperatures ◽  
Fundamental Problem ◽  
Scattering Rate ◽  
Phase Saturation ◽  
Long Range Interactions ◽  
Two Level Systems ◽  
Phase Decoherence ◽  
Dynamic Components

The fundamental problem of the phase saturation of electrons in a disordered mesoscopic system at very low temperatures is addressed. The disorder in the medium has both static and dynamic components, the latter being in the form of two-level systems (TLSs) which become just about the only source of inelastic scattering in the limit T → 0. We propose that besides the inelastic nature of scattering from the TLSs, the phase shift of the electrons is also affected by the nature of tunneling in the TLSs. The tunneling becomes incoherent as T decreases due to increasing long-range interactions among the TLSs which affects the phase coherence of electrons scattering from them. The competition between this effect, which increases as ~ T-1, and that of the scattering rate [Formula: see text] behaving as ~ T apparently govern the phase shift of the electrons.

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