Dependency of coercivity on Co layer thickness in Co/Cu multilayer structures

1997 ◽  
Vol 33 (5) ◽  
pp. 3529-3531 ◽  
Author(s):  
S.F. Cheng ◽  
V.G. Harris ◽  
G.A. Prinz
Keyword(s):  
Layer Thickness ◽  
Multilayer Structures

scholarly journals Assessment of Potential of the High-Voltage Anodic Plasma Source to Deposit Multilayer Structures Relevant to X-ray Mirror Applications

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 531
Author(s):  
Aurel-Mihai Vlaicu ◽  
Alexandru Anghel ◽  
Marius Badulescu ◽  
Cristina Surdu-Bob
Keyword(s):  
Film Thickness ◽  
Layer Thickness ◽  
Deposition Rate ◽  
High Voltage ◽  
Plasma Source ◽  
Multilayer Structures ◽  
Deposition Technique ◽  
X Ray ◽  
Coating Technique ◽  
Glass Substrates

(1) Background: The high-voltage anodic-plasma (HVAP) coating technique has a series of specificities that are not simultaneously met in other deposition methods. This paper aimed at assessing the potential of HVAP to synthesize quality multilayers for X-ray optics. (2) Methods: Nanolayers of W, Ta, B, and Si were deposited as mono-, bi-, and multilayers onto very smooth glass substrates by HVAP, and their thickness and density were analyzed by X-ray reflectometry. The minimal film thickness needed to obtain continuous nanolayers was also investigated. (3) Results: Nanolayer roughness did not increase with layer thickness, and could be lowered via deposition rate, with values as low as 0.6 for the W nanolayer. Minimal film thickness for continuous films for the studied metals was 4 nm (W), 6 nm (Ta), 2.5 nm (B), and 6 nm (Si). (4) Conclusions: The investigation revealed the range of parameters to be used for obtaining quality nanolayers and multilayers by HVAP. Advantages and possible improvements are discussed. This deposition technique can be tailored for demanding applications such as X-ray mirrors.

Uniform Low-Temperature Deposition of Optical Layers by Plasma-Activated CVD

1992 ◽  
Vol 269 ◽  
Author(s):  
Hans Lydtin ◽  
Arnd Ritz
Keyword(s):  
Low Temperature ◽  
Layer Thickness ◽  
Operation Mode ◽  
Plasma Source ◽  
Multilayer Structures ◽  
Dielectric Layers ◽  
Remote Operation ◽  
Temperature Deposition ◽  
Microwave Applicator ◽  
Materials Used

ABSTRACTPlasma activated CVD in a remote operation mode is applied to the deposition of dielectric layers on extended substrates. Layer thickness uniformity of ±1% over areas of 80mm diameter is demonstrated. The microwave applicator sustaining the plasma source of condensable species is compared in its deposition characteristic to conventional evaporation sources. Deposition efficiencies up to 70% are reached. The layer materials used are SiO2 and TiO2. Multilayer structures are prepared and optically characterized.

Effects of Periodic Structures on the Coherence Properties of Blackbody Radiation

2004 ◽  
Vol 126 (5) ◽  
pp. 786-792 ◽  
Author(s):  
L. Hu ◽  
A. Schmidt ◽  
A. Narayanaswamy ◽  
G. Chen
Keyword(s):  
Ray Tracing ◽  
Layer Thickness ◽  
Periodic Structures ◽  
Blackbody Radiation ◽  
Radiative Properties ◽  
Multilayer Structures ◽  
Wave Optics ◽  
Wave Interference ◽  
Radiation Sources ◽  
Random Structures

Radiative properties have been studied for one-dimensional dielectric multilayer structures subjected to blackbody radiation sources. The total hemispherical transmittances are calculated for periodic structures and structures with random variation in layer thickness, using wave-optics and ray-tracing methods. Simulation results show that for periodic structures, the transmittance calculated using wave optics approaches a nonzero constant value with an increasing number of layers, while the transmittance obtained using the ray-tracing method asymptotically approaches zero. For random structures, the transmittance given by wave optics drops to zero at different rates depending on the order of random variations in layer thickness. It is found that the wave interference effect always plays a role when dealing with multilayer structures. The results are explained based on extended and localized waves.

Structure and Orientation of As Precipitates in LT-MBE Grown GaAs

1991 ◽  
Vol 49 ◽  
pp. 900-901 ◽  
Author(s):  
Alain Claverie ◽  
Zuzanna Liliental-Weber
Keyword(s):  
Transport Properties ◽  
Layer Thickness ◽  
Growth Temperature ◽  
Low Temperatures ◽  
Lattice Parameter ◽  
Crystalline Quality ◽  
Insulating Properties ◽  
Lt Gaas

GaAs layers grown by MBE at low temperatures (in the 200°C range, LT-GaAs) have been reported to have very interesting electronic and transport properties. Previous studies have shown that, before annealing, the crystalline quality of the layers is related to the growth temperature. Lowering the temperature or increasing the layer thickness generally results in some columnar polycrystalline growth. For the best “temperature-thickness” combinations, the layers may be very As rich (up to 1.25%) resulting in an up to 0.15% increase of the lattice parameter, consistent with the excess As. Only after annealing are the technologically important semi-insulating properties of these layers observed. When annealed in As atmosphere at about 600°C a decrease of the lattice parameter to the substrate value is observed. TEM studies show formation of precipitates which are supposed to be As related since the average As concentration remains almost unchanged upon annealing.

The stabilization of B.C.C. Cu in Cu/Nb nanolayered composites

1996 ◽  
Vol 54 ◽  
pp. 228-229
Author(s):  
H. Kung ◽  
A.J. Griffin ◽  
Y.C. Lu ◽  
K.E. Sickafus ◽  
T.E. Mitchell ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Layer Thickness ◽  
Volume Fraction ◽  
Ion Beam ◽  
High Strength ◽  
Cross Sectional ◽  
Metastable Structure ◽  
High Resolution Tem ◽  
Potential Improvement ◽  
Two Phases

Materials with compositionally modulated structures have gained much attention recently due to potential improvement in electrical, magnetic and mechanical properties. Specifically, Cu-Nb laminate systems have been extensively studied mainly due to the combination of high strength, and superior thermal and electrical conductivity that can be obtained and optimized for the different applications. The effect of layer thickness on the hardness, residual stress and electrical resistivity has been investigated. In general, increases in hardness and electrical resistivity have been observed with decreasing layer thickness. In addition, reduction in structural scale has caused the formation of a metastable structure which exhibits uniquely different properties. In this study, we report the formation of b.c.c. Cu in highly textured Cu/Nb nanolayers. A series of Cu/Nb nanolayered films, with alternating Cu and Nb layers, were prepared by dc magnetron sputtering onto Si {100} wafers. The nominal total thickness of each layered film was 1 μm. The layer thickness was varied between 1 nm and 500 nm with the volume fraction of the two phases kept constant at 50%. The deposition rates and film densities were determined through a combination of profilometry and ion beam analysis techniques. Cross-sectional transmission electron microscopy (XTEM) was used to examine the structure, phase and grain size distribution of the as-sputtered films. A JEOL 3000F high resolution TEM was used to characterize the microstructure.

Investigation of ultra-thin films of YBa2Cu3O7−δ grown on MgO

1990 ◽  
Vol 48 (4) ◽  
pp. 6-7
Author(s):  
S.K. Streiffer ◽  
C.B. Eom ◽  
J.C. Bravman ◽  
T.H. Geballet
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Deposition Process ◽  
Nucleation And Growth ◽  
Multilayer Structures ◽  
Rf Power ◽  
Oxygen Loss ◽  
Transmission Electron ◽  
Single Target ◽  
Mtorr Argon

The study of very thin (<15 nm) YBa2Cu3O7−δ (YBCO) films is necessary both for investigating the nucleation and growth of films of this material and for achieving a better understanding of multilayer structures incorporating such thin YBCO regions. We have used transmission electron microscopy to examine ultra-thin films grown on MgO substrates by single-target, off-axis magnetron sputtering; details of the deposition process have been reported elsewhere. Briefly, polished MgO substrates were attached to a block placed at 90° to the sputtering target and heated to 650 °C. The sputtering was performed in 10 mtorr oxygen and 40 mtorr argon with an rf power of 125 watts. After deposition, the chamber was vented to 500 torr oxygen and allowed to cool to room temperature. Because of YBCO’s susceptibility to environmental degradation and oxygen loss, the technique of Xi, et al. was followed and a protective overlayer of amorphous YBCO was deposited on the just-grown films.

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