Specular Scattering in Electrical Transport in the Thin Tilm System CoSi2/Si

1984 ◽  
Vol 37 ◽  
Author(s):  
J. C. Hensel ◽  
R. T. Tung ◽  
J. M. Poate ◽  
F. C. Unterwald
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Size Effect ◽  
Electrical Transport ◽  
Low Temperatures ◽  
Boundary Scattering ◽  
Specular Scattering ◽  
Bulk Scattering ◽  
Scattering Lengths ◽  
High Degree

AbstractWe have investigated electrical transport in thin films of CoSi2 at low temperatures as a function of film thickness and observe in conductivity a size effect much smaller than seen heretofore indicative of a high degree of specularity in the boundary scattering. This in large part owes to the unique characteristics of these films, i.e., they are single crystal and continuous down to ∼60Å thickness with long bulk scattering lengths (≈1000Å) in transport at liquid He temperatures and have nearly atomically perfect interfaces.

Transport Properties of Granular Nix(SiO2)100−x Thin Films

1990 ◽  
Vol 195 ◽  
Author(s):  
John R. Beamish ◽  
B.M. Patterson ◽  
K.M. Unruh
Keyword(s):  
Thin Films ◽  
Temperature Dependence ◽  
Electrical Transport ◽  
Low Temperatures ◽  
Room Temperature ◽  
Volume Percent ◽  
Ni Content ◽  
Resistivity Minimum ◽  
Temperature Coefficient Of Resistivity ◽  
Sputter Deposited

ABSTRACTWe have studied the electrical transport behavior of sputter deposited Nix(SiO2)100−x thin films between room temperature and 100 mK and, at selected temperatures, in applied magnetic fields up to 6 T. As the Ni concentration x is reduced, the resistivity increases systematically. At a Ni concentration (nominal) of about x–70 atomic percent (38 volume percent) the room temperature coefficient of resistivity changes sign. For Ni concentrations greater than 70 percent the resistance first decreases with temperature then increases logarithmically at, low temperatures. This increase becomes smaller and the resistivity minimum moves to progressively lower temperatures as the Ni concentration increases. In films with less than x–70 percent Ni, the resistivity has a temperature dependence of the form ρ(T)–ρo exp \(To/T)α] between room temperature and about 5 K. The exponent a is about 1/2 and To increases with decreasing Ni content. Below 1 K, however, the resistivity increases much less rapidly, with a temperature dependence independent of Ni concentration. In all films the magnetoresistance is small and negative.

FINITE SIZE EFFECT ON YBCO/PBCAO AND YBCO/PBCGO NANOMETER MULTILAYERS

2013 ◽  
Vol 27 (15) ◽  
pp. 1362009
Author(s):  
TAR-PIN CHEN ◽  
KE WU ◽  
S. Z. WANG ◽  
QI LI ◽  
BENJAMIN CHEN ◽  
...  
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Size Effect ◽  
Ybco Film ◽  
Finite Size ◽  
Finite Size Effect ◽  
Ybco Films ◽  
Electrical Resistivities ◽  
Superconducting Onset Temperature ◽  
2D To 3D

We have fabricated (110) epitaxy YBa 2 Cu 3 O 7-δ (YBCO), PrBa 2 Cu 0.8 Al 0.2 O 7 (PBCAO), PrBa 2 Cu 0.8 Ga 0.2 O 7-δ (PBCGO) nanometer-thin films and YBCO/PBCAO, YBCO/PBCGO multilayers of a variety of film thicknesses. Electrical resistivities measured from these systems were plotted against temperatures and film thicknesses and are presented in this paper. Superconducting onset temperature Tc of the YBCO films was estimated and plotted against YBCO film thickness. Superconducting coupling length was deduced. Finite size effect and 2D to 3D transition are also discussed.

A TEM study of microstructures of YBa2Cu3O7−x thin films deposited on LaAlO3 by laser ablation

1991 ◽  
Vol 6 (9) ◽  
pp. 1823-1828 ◽  
Author(s):  
S.N. Basu ◽  
A.H. Carim ◽  
T.E. Mitchell
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Film Thickness ◽  
Single Crystal ◽  
Grain Boundaries ◽  
Misfit Dislocations ◽  
High Angle ◽  
Interfacial Structures ◽  
High Degree ◽  
Periodic Spacing

The microstructures of YBa2Cu3O7−x thin films deposited by laser ablation on single crystal (001) LaAlO3 substrates have been investigated. The orientation of the YBa2Cu3O7−x layer next to the interface is found to be completely c-perpendicular, with a high degree of epitaxy between the film and the substrate. Misfit dislocations, with a periodic spacing of around 13 nm, are present at the interface. Two distinct interfacial structures are seen in these films. At a film thickness of around 400 nm, nucleation of c-parallel grains occurs, leading to a switchover from a c, and, and-perpendicular to a c-parallel microstructure. Amorphous particulates, ejected from the target during processing, lead to the formation of misoriented grains, giving rise to high-angle grain boundaries in the film.

Electrical Transport in thin Silicide Films

1985 ◽  
Vol 54 ◽  
Author(s):  
J. C. Hensel
Keyword(s):  
Thin Film ◽  
Hall Effect ◽  
Size Effects ◽  
Electrical Transport ◽  
Boundary Scattering ◽  
Band Theory ◽  
Carrier Scattering ◽  
Electronic Parameters ◽  
Scattering Lengths ◽  
Classical Size

ABSTRACTThis paper reviews our recent studies of electrical transport in thin suicide films. Resistivity as a function of temperature, Hall effect, and magnetoresistance have been characterized for CoSi2 and NiSi2 and in conjunction with band theory provide estimates of important electronic parameters, viz. carrier densities and carrier scattering lengths. Resistivity data for TiSi2 and TaSi2 are included. Also examined in resistivity are (i) effects produced by ion bombardment which show CoSi2 to have an unusual susceptibility to radiation damage and (ii) classical size effects in the very thin film regime which show the boundary scattering to be principally specular. As an application we describe a Si/CoSi2/Si heterostructure transistor recently developed.

Electrical Transport in Ultrathin Films of CoSi2 on Si(111)

1987 ◽  
Vol 91 ◽  
Author(s):  
J. C. Hensel ◽  
J. M. Phillips ◽  
J. L. Batstone ◽  
W. M. Augustyniak ◽  
F. C. Unterwald
Keyword(s):  
Film Thickness ◽  
Size Effect ◽  
Ultrathin Films ◽  
Electrical Transport ◽  
Weak Localization ◽  
Temperature Characteristic ◽  
Inverse Temperature ◽  
Quantum Size ◽  
Temperature Dependences ◽  
Hall Effect Measurements

ABSTRACTWe have performed electrical transport measurements on ultrathin films of epitaxial CoSi2 on Si(111) with film thickness ranging down to ∼10A. The resistivities exhibit temperature dependences characteristic of a metal and a thickness dependence which rises steeply with decreasing thickness suggestive of a quantum size effect. At the lowest temperatures (≲ 10K) the resistivities of the thinner films increase logarithmically with inverse temperature characteristic of transport in the weak localization regime as has been confirmed by magnetoresistance measurements. Hall effect measurements establish that carrier densities (holes) in the ultrathin films are essentially identical to those in bulk CoSi2, i.e. 26 × 1022 cm−3.

Investigation of Size Effect on the Emissivity of Thin Films

2012 ◽  
Author(s):  
Sheila Edalatpour ◽  
Mathieu Francoeur
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Size Effect ◽  
Critical Thickness ◽  
Model Simulation ◽  
Direct Method ◽  
Approximate Expression ◽  
Multiple Reflections ◽  
The Mathematical Model ◽  
Kirchhoff's Law

The size effect on the emissivity of thin films is analyzed via a direct method based on Maxwell’s equations combined with fluctuational electrodynamics. Traditional indirect approaches involve computation of absorption, and the emissivity is then predicted by invoking Kirchhoff’s law. The direct method employed in this work does not require Kirchhoff’s law. Instead, Kirchhoff’s law emerges naturally from the mathematical model. Simulation results reveal that the emissivity of metal films increase above bulk values as the film thickness decreases. This counterintuitive behavior is due to the extraneous contributions of waves experiencing multiple reflections within the thin layer, which are usually internally absorbed for metallic bulks. Conversely, for dielectrics, the emissivity of films decreases as the film thickness decreases due to a loss of source volume. The critical thickness above which no size effect is observed for metals is about a hundred of nanometers, while it is as large as a few centimeters for dielectrics. Finally, a simple approximate expression is suggested for evaluating the critical thickness; this expression can be used as a quick reference to determine if the size effect on the emissivity of thin films should be considered.

Effects of Deposition Temperature and Film Thickness on the Structural, Electrical, and Optical Properties of Germanium Thin Films

2002 ◽  
Vol 715 ◽  
Author(s):  
William B. Jordan ◽  
Sigurd Wagner
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Film Thickness ◽  
Vapor Deposition ◽  
Electrical Transport ◽  
Deposition Temperature ◽  
High Mobility ◽  
Chemical Vapor ◽  
Electrical Transport Properties ◽  
Electrical And Optical Properties

AbstractGermanium films deposited on glass by plasma-enhanced chemical vapor deposition from germane and hydrogen grow in the structure succession of amorphous-nanocrystallineamorphous-nanocrystalline as the substrate temperature is raised from 30°C to 310°C. We ascribe the phase formation, from low to high temperature, to a sequence of low to high mobility of Ge growth species on a surface that is hydrogenated at low temperature but not hydrogenated at high temperature. We report some structural, optical, and electrical transport properties of Ge films as a function of deposition temperature and film thickness.

scholarly journals Determination of Dielectric Constant of Stearic Acid Films Using Varying Gap Immersion Method

1977 ◽  
Vol 4 (1) ◽  
pp. 23-28 ◽  
Author(s):  
V. K. Agarwal ◽  
B. Ichijo
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Film Thickness ◽  
Stearic Acid ◽  
Reasonable Agreement ◽  
Langmuir Films ◽  
Immersion Method ◽  
Experimental Tool ◽  
High Degree

The dielectric constant data (at 3.5 MHz) on stearic acid thin films, obtained by using variable gap immersion method, are presented. Many of the errors of the conventional universal bridge method are eliminated in the method used here. It is also shown that the varying gap immersion method serves as an experimental tool for simultaneous determination of film thickness with high degree of accuracy. The data on evaporated as well as Langmuir films of stearic acid (≥1000 Å) are found to be consistent and in reasonable agreement.

Specular Boundary Scattering and Electrical Transport in Single-Crystal Thin Films of CoSi2

1985 ◽  
Vol 54 (16) ◽  
pp. 1840-1843 ◽  
Author(s):  
J. C. Hensel ◽  
R. T. Tung ◽  
J. M. Poate ◽  
F. C. Unterwald
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Electrical Transport ◽  
Boundary Scattering
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