Microscratch analysis of the work of adhesion for Pt thin films on NiO

1992 ◽  
Vol 7 (5) ◽  
pp. 1126-1132 ◽  
Author(s):  
S. Venkataraman ◽  
D.L. Kohlstedt ◽  
W.W. Gerberich
Keyword(s):  
Thin Films ◽  
Strain Energy ◽  
Reasonable Agreement ◽  
Sample Surface ◽  
Work Of Adhesion ◽  
Elastic Contact ◽  
Interfacial Fracture Toughness ◽  
Load Drop ◽  
Metal Ceramic ◽  
Scratch Track

The adhesion of as-sputtered Pt thin films to NiO single crystals has been characterized by a continuous microscratch technique. In these experiments, a conical indenter was driven into a 1.2 μm thick Pt film at a rate of 15 nm/s, and across the sample surface at a rate of 0.5 μm/s, until a load drop was observed indicating that the film had delaminated. Using the width of the scratch track at the point at which the film delaminated from the substrate, the critical load required for delamination, and the area of the delaminated region, a model has been developed to determine the work of adhesion of the Pt/NiO system. This model uses an elastic contact mechanics approach to relate the stresses acting in a scratch experiment to the strain energy released during film delamination. Using this model, the work of adhesion and hence the interfacial fracture toughness have been determined to be 0.023–0.06 J/m2 and 0.07–0.11 MPa$\sqrt m$, respectively. These values are in reasonable agreement with those determined by other methods for metal-ceramic systems.

Continuous Microindentation and Microscratch Measurements of Metal-Ceramic Adhesive strengths

1991 ◽  
Vol 239 ◽  
Author(s):  
S. Venkataraman ◽  
D. L. Kohlstedt ◽  
W. W. Gerberich
Keyword(s):  
Fracture Toughness ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Strain Energy Release ◽  
Interfacial Fracture ◽  
Interfacial Shear ◽  
Work Of Adhesion ◽  
Interfacial Fracture Toughness ◽  
Heat Treated ◽  
Metal Ceramic

ABSTRACTTo investigate the effect of heat-treatment on the adhesion of Pt thin films to NiO substrates, the strain energy release rate, interfacial fracture toughness and interfacial shear strength were determined from continuous microscratch and continuous microindentation experiments. Samples were prepared by sputtering Pt onto single crystals of NiO, followed by a heat-treatment at temperatures of 300, 500 and 800°C and an oxygen partial pressure of either 0.21 or 10-5 atm. Continuous microscratch tests were performed by driving a conical indenter with either a 1 or 5 μm tip radius simultaneously into and across the Pt film. From the magnitude of the critical load at the point of film delamination and the area of the delaminated piece of the thin film, the strain energy release rate (practical work of adhesion) and interfacial fracture toughness were calculated. The practical work of adhesion and interfacial fracture toughness increased from 0.2 J/m2 and 0.2 MPa√m, respectively, for as-sputtered samples to 4.6 J/m2 and 1 MPa√m for samples heat-treated at 500°C and 10-5 atm. Preliminary analysis of continuous microindentation results for Pt/NiO samples yielded interfacial shear strengths of 270 MPa for as-sputtered samples and 725 MPa for samples heat-treated at 500°C and 10-5 atm. While these values are in good agreement with those determined by other methods for metal-ceramic systems, there are sufficient differences in test method for a single system to require additional analysis of the proposed models.

A technique to prepare cross-sectional TEM specimens of semiconducting devices

1986 ◽  
Vol 44 ◽  
pp. 742-743
Author(s):  
A. K. Rai ◽  
P. P. Pronko
Keyword(s):  
Thin Films ◽  
Surface Region ◽  
Sample Surface ◽  
Specific Region ◽  
Cross Sectional ◽  
Thin Sections ◽  
The Past ◽  
Device Structures ◽  
Ion Implanted

Several techniques have been reported in the past to prepare cross(x)-sectional TEM specimen. These methods are applicable when the sample surface is uniform. Examples of samples having uniform surfaces are ion implanted samples, thin films deposited on substrates and epilayers grown on substrates. Once device structures are fabricated on the surfaces of appropriate materials these surfaces will no longer remain uniform. For samples with uniform surfaces it does not matter which part of the surface region remains in the thin sections of the x-sectional TEM specimen since it is similar everywhere. However, in order to study a specific region of a device employing x-sectional TEM, one has to make sure that the desired region is thinned. In the present work a simple way to obtain thin sections of desired device region is described.

scholarly journals Synthesis of tunable plasmonic metal-ceramic nanocomposite thin films by temporally modulated sputtered fluxes

2017 ◽  
Vol 121 (17) ◽  
pp. 171918 ◽  
Author(s):  
D. Magnfält ◽  
E. Melander ◽  
R. D. Boyd ◽  
V. Kapaklis ◽  
K. Sarakinos
Keyword(s):  
Thin Films ◽  
Nanocomposite Thin Films ◽  
Metal Ceramic ◽  
Ceramic Nanocomposite

scholarly journals Nucleation Studies of HfO2 Thin Films Produced by Atomic Layer Deposition

2007 ◽  
Vol 996 ◽  
Author(s):  
Justin C. Hackley ◽  
J. Derek Demaree ◽  
Theodosia Gougousi
Keyword(s):  
Thin Films ◽  
Atomic Layer Deposition ◽  
Photoelectron Spectroscopy ◽  
Flow Reactor ◽  
Atomic Layer ◽  
Sample Surface ◽  
Interfacial Region ◽  
Initial Growth ◽  
Layer Deposition ◽  
Similar Growth

AbstractA hot wall Atomic Layer Deposition (ALD) flow reactor equipped with a Quartz Crystal Microbalance (QCM) has been used for the deposition of HfO2 thin films with tetrakis (dimethylamino) hafnium (TDMAH) and H2O as precursors. HfO2 films were deposited on H-terminated Si and SC1 chemical oxide starting surfaces. Spectroscopic ellipsometry (SE) and QCM measurements confirm linear growth of the films at a substrate temperature of 275°C. FTIR spectra indicate the films are amorphous as-deposited. Two distinct growth regimes are observed: from 1-50 cycles, both surfaces display similar growth rates of about 1.0Å/cycle; from 50-200 cycles, HfO2 growth is decreased by about 15% to ~0.87Å/cycle on both surfaces. Nucleation and initial growth behavior of the films on Si-H were examined using X-ray photoelectron spectroscopy (XPS). Angle-resolved XPS, at take-off angles of θ=0, 15, 30, 45 and 60° measured from the normal to the sample surface, is used to probe the interfacial region of thin films (4, 7, 10, 15 and 25 cycles) on H-terminated samples. Initially, an interfacial layer comprised of a SiOx/HfSiOx mixture is grown between 1-10 ALD cycles. We observe that the Si/HfO2 interface is unstable, and oxidation continues up to the 25th ALD cycle, reaching a thickness of ~18Å.

Thermodynamic modeling of elastic mismatch strain energy on epitaxial growth of GaInN thin films

2019 ◽  
Vol 798 ◽  
pp. 112-118
Author(s):  
Xinyuan Hu ◽  
Lei L. Kerr ◽  
Xushan Zhao ◽  
Chen Ling ◽  
Zhengjing Zhao ◽  
...  
Keyword(s):  
Thin Films ◽  
Epitaxial Growth ◽  
Thermodynamic Modeling ◽  
Strain Energy ◽  
Mismatch Strain ◽  
Elastic Mismatch

scholarly journals Effect of Precursor Concentration on Structural Optical and Electrical Properties of NiO Thin Films Prepared by Spray Pyrolysis

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Rafia Barir ◽  
Boubaker Benhaoua ◽  
Soufiane Benhamida ◽  
Achour Rahal ◽  
Toufik Sahraoui ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Spray Pyrolysis ◽  
Sample Surface ◽  
Precursor Concentration ◽  
Spray Pyrolysis Method ◽  
Nitrate Hexahydrate ◽  
Optical And Electrical Properties ◽  
Sem Images ◽  
Nano Structure

Undoped nickel oxide (NiO) thin films were deposited on 500°C heated glass substrates using spray pyrolysis method at (0.015–0.1 M) range of precursor. The latter was obtained by decomposition of nickel nitrate hexahydrate in double distilled water. Effect of precursor concentration on structural, optical, and electrical properties of NiO thin films was investigated. X-ray diffraction (XRD) shows the formation of NiO under cubic structure with single diffraction peak along (111) plane at 2θ=37.24°. When precursor concentration reaches 0.1 M, an increment in NiO crystallite size over 37.04 nm was obtained indicating the product nano structure. SEM images reveal that beyond 0.04 M as precursor concentration the substrate becomes completely covered with NiO and thin films exhibit formation of nano agglomerations at the top of the sample surface. Ni-O bonds vibrations modes in the product of films were confirmed by FT-IR analysis. Transparency of the films ranged from 57 to 88% and band gap energy of the films decreases from 3.68 to 3.60 eV with increasing precursor concentration. Electrical properties of the elaborated NiO thin films were correlated to the precursor concentration.

First Principles Calculations for Metal/Ceramic Interfaces

1994 ◽  
Vol 357 ◽  
Author(s):  
M. W. Finnis ◽  
C. Kruse ◽  
U. SchÖnberger
Keyword(s):  
Electronic Structure ◽  
High Resolution ◽  
Ab Initio ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Work Of Adhesion ◽  
First Principles Calculations ◽  
Resolution Electron ◽  
Metal Ceramic

AbstractWe discuss the recent first principles calculations of the properties of interfaces between metals and oxides. This type of calculation is parameter-free, and exploits the density functional theory in the local density approximation to obtain the electronic structure of the system. At the same time the equilibrium atomic structure is sought, which minimises the excess energy of the interface. Up to now calculations of this type have been made for a few model interfaces which are atomically coherent, that is with commensurate lattices. Examples are Ag/MgO and Nb/Al2O3. In these cases it has been possible to predict the structures observed by high resolution electron microscopy. The calculations are actually made in a supercell geometry, in which there are alternating nanolayers of metal and ceramic. Because of the effectiveness of metallic screening in particular, the interfaces between the nanolayers do not interfere much with each other.Besides the electronic structure of the interface, such calculations have provided values of the ideal work of adhesion. Electrostatic image forces in conjunction with the elementary ionic model provide a simple framework for understanding the results.An important role of such calculations is to develop intuition about the nature of the bonding, including the effects of charge transfer, which has formerly only been described in an empirical way. It may then be possible to build atomistic models of the metal/ceramic interaction which have a sound physical basis and can be calibrated against ab initio results. Simpler models are necessary if larger systems, including misfit dislocations and other defects, are to be simulated, with a view to understanding the atomic processes of growth and failure. Another area in which ab initio calculations can be expected to contribute is in the chemistry of impurity segregation and its effect at interfaces. Such theoretical tools are a natural partner to the experimental technique of high resolution electron energy loss spectroscopy for studying the local chemical environment at an interface.

Bifurcation in deformation mechanism to overcome strength-ductility paradox in metal-ceramic multilayer thin-films

2018 ◽  
Vol 113 (10) ◽  
pp. 101902
Author(s):  
Tarang Mungole ◽  
Bilal Mansoor ◽  
Georges Ayoub ◽  
David P. Field
Keyword(s):  
Thin Films ◽  
Deformation Mechanism ◽  
Multilayer Thin Films ◽  
Metal Ceramic
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