Lack of hardening effect in TiN/NbN multilayers

2001 ◽  
Vol 673 ◽  
Author(s):  
Jon M. Molina-Aldareguia ◽  
Stephen J. Lloyd ◽  
Zoe H. Barber ◽  
William J. Clegg
Keyword(s):  
Multilayer Films ◽  
Dislocation Motion ◽  
Deformation Mechanisms ◽  
Modulation Amplitude ◽  
Reactive Magnetron ◽  
Interface Thickness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Composition Modulation ◽  
Nanoindentation Hardness

ABSTRACTThere is evidence indicating that multilayer films can be harder than monolithic ones. To investigate this, TiN/NbN multilayers with bilayer thicknesses ranging from 4 nm to 30 nm have been grown on MgO (001) single crystals using reactive magnetron sputtering. The sharpness of the interface and the composition modulation, which would be expected to strongly influence dislocation motion, have been studied by X-ray diffraction (XRD). These experiments show that the interfaces remain reasonably sharp (interface thickness ∼1 nm) and the composition modulation amplitude is maximum for multilayers with bilayer thicknesses greater than ∼10 nm. With thinner bilayers, the composition modulation decreases but the layered structure remains. Despite this, the nanoindentation hardness of the multilayers is between 20 and 25 GPa, which is similar to that of TiN and NbN alone, and therefore, no hardening due to the layering is observed. The deformation mechanisms observed under the indent in the TEM are consistent with these results.

Structure And Mechanical Properties Of Reactive Sputter Deposited Tin/Tan Multilayered Films

1997 ◽  
Vol 505 ◽  
Author(s):  
W.-H. Soe ◽  
T. Kitagaki ◽  
H. Ueda ◽  
N. Shima ◽  
M. Otsuka ◽  
...  
Keyword(s):  
Diffraction Method ◽  
Dislocation Motion ◽  
X Ray Diffraction ◽  
Multilayered Films ◽  
X Ray ◽  
Composition Modulation ◽  
Hardness Change ◽  
Sputter Deposited ◽  
Coherency Strains ◽  
Hardness Values

ABSTRACTTiN/TaN multilayers were grown by reactive magnetron sputtering on WC-Co sintered hard alloy and MgO(100) single crystal substrates. Multilayer structure and composition modulation amplitudes were studied using x-ray diffraction method. Hardness and elastic modulus were mea- sured by nanoindentation tester. For bilayer thickness (Λ) larger than 80 A˚, hardness are lower than rule-of-mixtures value of individual single layers, and increased rapidly with decreasing Λ, peaking at hardness values ≈33% higher than that at A=43 Å. As a result of analysis the inclination of applied load for indenter displacement on P-h curve (ΔP/Δh), this paper exhibits that the en- hancement of the resistance to dislocation motion and elastic anomaly due to coherency strains are responsible for the hardness change.

Microstructure, Mechanical Properties and Thermal Stability of TiAlN/Si3N4 Nano-Multilayer Films Deposited by Reactive Magnetron Sputtering

2009 ◽  
Vol 79-82 ◽  
pp. 489-492
Author(s):  
Jiang Ling Yue ◽  
Yan Sheng Yin ◽  
Ge Yang Li
Keyword(s):  
Mechanical Properties ◽  
Magnetron Sputtering ◽  
Layer Thickness ◽  
Multilayer Films ◽  
Reactive Magnetron Sputtering ◽  
Reactive Magnetron ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si3n4 Layer ◽  
Superlattice Structure

A series of TiAlN/Si3N4 nano-multilayer films with various Si3N4 layer thicknesses were prepared by reactive magnetron sputtering. These multilayers were then annealed at temperatures ranging from 600 to 900°C in air for 1 hour. The composition, microstructure, and mechanical properties of the films were characterized by energy dispersive x-ray spectroscopy, x-ray diffraction, scanning electron microscopy, and nanoindentation. It reveals that under the template effect of TiAlN layers in multilayers, as-deposited amorphous Si3N4 is crystallized and grows coherently with TiAlN layers when Si3N4 layer thickness is below 0.6 nm. Correspondingly, the hardness and elastic modulus of the multilayers increase significantly. With further increase in the layer thickness, Si3N4 transforms into amorphous, resulting in a decrease of hardness and modulus. The TiAlN/Si3N4 nano-multilayers could retain their superlattice structure even up to 900°C. The small decrease in the hardness of multilayers annealed below 800°C was correlated to the release of compressive stress in multilayers. However, oxidation was found on the surface of multilayers when annealed at 800°C, which resulted in a marked decrease in the hardness of multilayers. The multilayers presented higher hardness as compared with the monolithic TiAlN film.

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.

Structural Properties Of Co/Re Superlattices

1991 ◽  
Vol 238 ◽  
Author(s):  
Y. Huai ◽  
R. W. Cochrane ◽  
Y. Shi ◽  
H. E. Fischer ◽  
M. Sutton
Keyword(s):  
Structural Disorder ◽  
Multilayer Films ◽  
Film Plane ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bilayer Films ◽  
Out Of Plane ◽  
Reflectivity Data ◽  
Sharp Interfaces ◽  
Good Agreement

ABSTRACTThe structures of equal-thickness Co/Re multilayer films and several Co/Re bilayer films have been investigated by X-ray diffraction at low and high angles. Analysis of low-angle reflectivity data from bilayer films indicates that interfacial intermixing is limited to three monolayers and that the two interfacial configurations are different. The high-angle X-ray diffraction data show that multilayer films have coherent interfaces and a highly textured structure with hep [002] orientations normal to the film plane for periods 21 Å ≤ Λ ≤220 Å. Detailed structures have been determined by fitting the X-ray spectra to calculated ones using a trapezoidal model. The results indicate that samples with 42 Å≤ Λ ≤220 Å have relatively sharp interfaces, in good agreement with the bilayer results. In addition, an out-of-plane expansion of the Co (002) layer is observed in samples with large Λ and results from structural disorder leading to a reduced atomic density. For Λ <21 Å the interfaces arise from the rougher surfaces of the deposited layers.

THE GIANT MAGNETOSTRICTION OF [Fe/Tb/Fe/Dy]n MULTILAYER FILMS UNDER DIFFERENT ANNEALING TEMPERATURE

2009 ◽  
Vol 16 (01) ◽  
pp. 123-126 ◽  
Author(s):  
X. D. LI ◽  
Z. J. ZHAO ◽  
T. FENG ◽  
L. K. PAN ◽  
S. M. HUANG ◽  
...  
Keyword(s):  
Saturation Magnetization ◽  
Annealing Temperature ◽  
Multilayer Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Low Field ◽  
Giant Magnetostriction

The effect of annealing temperature on the magnetic and giant magnetostriction (GMS) of [ Fe / Tb / Fe / Dy ]n multilayer films were investigated. X-ray diffraction showed that the multilayer films' microstructures were still in amorphous at annealing temperature 300°C. The multilayer films began to crystalline at annealing temperature 400°C. The saturation magnetization of multilayer films increased by the increasing annealed temperature. The coercivity first decreased at annealing temperature 300°C and then increased when the annealing temperature was higher than 400°C. The multilayer films had good low-field GMS, and the magnetostriction of the multilayer films increased by the increasing annealing temperature.

Crystal plasticity in shock-compressed hcp-iron

2021 ◽  
Author(s):  
Sébastien Merkel ◽  
Sovanndara Hok ◽  
Cynthia Bolme ◽  
Wendy Mao ◽  
Arianna Gleason
Keyword(s):  
Free Electron ◽  
Deformation Mechanisms ◽  
Free Electron Lasers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hexagonal Close Packed ◽  
Planetary Cores ◽  
Materials Behavior ◽  
Optical Laser

&lt;p&gt;Iron is a key constituent of planetary core and an important technological material. Here, we combine &lt;em&gt;in situ&lt;/em&gt; ultrafast X-ray diffraction at free electron lasers with optical-laser-induced shock compression experiments on polycrystalline Fe to study the plasticity of hexagonal close-packed (hcp)-Fe under extreme loading states. We identifiy the deformation mechanisms that controls the Fe microstructures and&amp;#160; observe a significant time-evolution of stress over the few nanoseconds of the experiments. These observations illustrate how ultrafast plasticity studies can reveal distinctive materials behavior under extreme loading states and will help constraining the pressure, temperature, and strain rate dependence of materials behavior in planetary cores.&lt;/p&gt;

Self-Assembly of Inorganic/Organic Multilayer Films

1994 ◽  
Vol 351 ◽  
Author(s):  
Astrid C. Zeppenfeld ◽  
Catherine J. Page
Keyword(s):  
Self Assembly ◽  
Grazing Angle ◽  
Multilayer Films ◽  
Silicon Wafers ◽  
Initial Surface ◽  
X Ray Diffraction ◽  
Individual Layer ◽  
X Ray ◽  
Influence Of Substrate ◽  
The Individual

ABSTRACTIn order to investigate the influence of substrate functionalization on the subsequent selfassembly of multilayer films, multilayers composed of alternating hafnium and 1,10-decanediylbis(phosphonic) acid (DBPA) have been grown on three different substrates. Substrates studied include gold wafers functionalized with 4-mercaptobutylphosphonic acid, silicon wafers functionalized using a hafnium oxychloride solution, and silicon wafers coated with an octadecylphosphonate LB-template layer. The nature of these films is probed using ellipsometry and grazing angle x-ray diffraction. These studies indicate that the overall order and the individual layer thickness can vary substantially from sample to sample and depend strongly on the initial surface functionalization prior to multilayer growth.

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