Micro- And Nano-Mechanical Behavior of Diamondlike Carbon Containing Foreign Atoms Prepared by Pulsed Laser Deposition

1998 ◽  
Vol 555 ◽  
Author(s):  
Q. Wei ◽  
R. J. Narayan ◽  
A. K. Sharma ◽  
J. Sankar ◽  
S. Oktyabrsky ◽  
...  
Keyword(s):  
Short Range ◽  
Random Network ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Internal Stresses ◽  
Spectroscopy Analysis ◽  
Stress Changes ◽  
Diamondlike Carbon ◽  
Target Design ◽  
Continuous Random Network

AbstractWe have prepared diamondlike carbon (DLC) films using KrF excimer pulsed laser (248 nm). The DLC films were deposited on Si (100) substrates and Cu and Ti were incorporated into the films through adopting a new target design. Visible Raman spectroscopy analysis of G-peak was correlated to internal stress changes in the DLC films due to incorporation of foreign atoms. Reduction of internal stresses in the presence of foreign atoms was established. This is consistent with adhesion studies that showed significant improvement in adhesion of DLC films containing dopants. Nanohardness and Young's modulus of DLC films containing Ti and Cu showed some decrease as compared to pure DLC. The experimental results are discussed in terms of the effect of dopants on the short range environment of the continuous random network (CRN) of DLC.

Growth of TiN/AlN Superlattice by Pulsed Laser Deposition

2002 ◽  
Vol 750 ◽  
Author(s):  
H. Wang ◽  
A. Gupta ◽  
Ashutosh Tiwari ◽  
X. Zhang ◽  
J. Narayan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Pulsed Laser Deposition ◽  
High Speed ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Internal Stresses ◽  
Layer By Layer ◽  
Special Configuration ◽  
Transmission Electron

ABSTRACTTiN-AlN binary-components have attracted a lot of interests in coatings of high speed cutting tools, due to their higher oxidation resistance, higher hardness, lower internal stresses and better adhesion. Especially, nanometer-scale multilayer structures of AlN/TiN show superior structural and mechanical properties due to their tremendous interface area and become one of the promising candidates for superhard coatings. Here we present a novel method to grow highly aligned TiN/AlN superlattice by pulsed laser deposition. In this method TiN and AlN targets are arranged in a special configuration that they can be ablated in sequence, giving alternate layer by layer growth of TiN(1nm)/AlN(4nm). X-ray diffraction and transmission electron microscopy (TEM) analysis showed the structure to be cubic for both TiN and AlN in the nanoscale multilayers. Microstructure and uniformity for the superlattice structure were studied by TEM and Scanning transmission electron microscopy with Z-contrast (STEM). Nanoindentation results indicated a higher hardness for this new structure than pure AlN and rule-of-mixtures value. Four point probe electrical resistivity measurements showed overall insulating behavior.

Degradation of Copper-Silver Alloy Thin Films Induced by Annealing

2005 ◽  
Vol 887 ◽  
Author(s):  
S. T. Snyder ◽  
Alex King
Keyword(s):  
Thin Films ◽  
Short Range ◽  
Eutectic Composition ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Silver Alloy ◽  
Free Standing ◽  
Diffusion Effects ◽  
Alloy Target ◽  
Short Times

ABSTRACTCopper / silver alloy thin films form with a fine, polycrystalline, metastable crystal structure. The expected effects of annealing include grain growth, transformation into the two stable phases, coarsening of the phases, texture formation, and the formation and growth of pinholes or voids. Copper/silver alloy films were deposited on single crystal sodium chloride substrates, via pulsed laser deposition ablation of an alloy target, of the eutectic composition. Free-standing films of 20-30 nm thickness were studied as-deposited and after annealing on copper TEM grids at 100°C for various times. Although several of the expected degradation processes involve short-range diffusion – essentially single atomic jumps – these were not observed, while other, longer-range diffusion effects were clearly identifiable. In particular, void shrinkage was observed in the films at short times, and void growth occurred at longer times.

PULSED LASER DEPOSITION OF DIAMONDLIKE CARBON FILMS IN DIFFERENT AMBIENT ATMOSPHERES

2004 ◽  
Author(s):  
MARCO BONELLI ◽  
ANTONIO MIOTELLO ◽  
PAOLO MOSANER ◽  
CINZIA CASIRAGHI ◽  
PAOLO M. OSSI
Keyword(s):  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Carbon Films ◽  
Laser Deposition ◽  
Diamondlike Carbon

Atomic structure, electrical properties, and infrared range optical properties of diamondlike carbon films containing foreign atoms prepared by pulsed laser deposition

2000 ◽  
Vol 15 (3) ◽  
pp. 633-641 ◽  
Author(s):  
Q. Wei ◽  
J. Sankar ◽  
A. K. Sharma ◽  
S. Oktyabrsky ◽  
J. Narayan ◽  
...  
Keyword(s):  
Optical Properties ◽  
Pulsed Laser Deposition ◽  
Atomic Structure ◽  
Pulsed Laser ◽  
Localized States ◽  
Laser Deposition ◽  
Infrared Range ◽  
Diamondlike Carbon ◽  
Gap States ◽  
Type Conduction

We investigated the atomic structure, electrical, and infrared range optical properties of diamondlike carbon (DLC) films containing alloy atoms (Cu, Ti, or Si) prepared by pulsed laser deposition. Radial distribution function (RDF) analysis of these films showed that they are largely sp3 bonded. Both pure DLC and DLC + Cu films form a Schottky barrier with the measuring probe, whereas DLC + Ti films behave like a linear resistor. Pure DLC films and those containing Cu exhibit p-type conduction, and those containing Ti and Si have n-type conduction. Photon-induced conduction is observed for pure DLC, and the mechanism is discussed in terms of low-density gap states of highly tetrahedral DLC. Our results are consistent with relative absence of gap states in pure DLC, in accordance with theoretical prediction by Drabold et al.37 Temperature dependence of conductivity of DLC + Cu shows a behavior σ ∞ exp(−B/T1/2), instead of the T−1/4 law (Mott–Davis law). Contributions from band-to-band transitions, free carriers, and phonons to the emissivity spectrum are clearly identified in pure DLC films. The amorphous state introduces a large contribution from localized states. Incorporation of a small amount of Si in the DLC does not change the general feature of emissivity spectrum but enhances the contribution from the localized states. Cu and Ti both enhance the free carrier and the localized state contributions and make the films a black body.

Pulsed laser deposition and laser machining of diamondlike carbon films

1998 ◽  
Author(s):  
Sergio Martellucci ◽  
Giovanni Messina ◽  
A. Paoletti ◽  
Maria Richetta ◽  
S. Santangelo ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Carbon Films ◽  
Laser Deposition ◽  
Laser Machining ◽  
Diamondlike Carbon

Formation of Biaxially Textured MgO Buffer Layers using Ion-Beam Assisted Pulsed Laser Deposition

2000 ◽  
Vol 659 ◽  
Author(s):  
Ruben Hühne ◽  
Christoph Beyer ◽  
Bernhard Holzapfel ◽  
Carl-Georg Oertel ◽  
Ludwig Schultz ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Single Crystals ◽  
Ion Beam ◽  
Pulsed Laser ◽  
Cube Texture ◽  
Buffer Layers ◽  
Laser Deposition ◽  
Internal Stresses ◽  
Nucleation Layer ◽  
Amorphous Substrates

ABSTRACTMgO thin films were deposited on amorphous substrates using ion-beam assisted pulsed laser deposition. The texture formation was investigated in-situ with RHEED. The microstructure of the films was observed by AFM. Using an ion beam at an angle of 55° with respect to the substrate normal, strong nucleation textures develop. Above 250°C a cube texture is observed in films thinner than 10 nm. During further growth this nucleation texture changes in a way that the <200> direction becomes parallel to the ion beam. This change can be explained by the anisotropic sputter rate of MgO found in sputter experiments on single crystals. Moreover, MgO films were deposited homoepitaxially on MgO single crystals above 250°C with internal stresses dreasing with increasing deposition temperature. This result gives rise to hope that homoepitaxial growth of MgO on the nucleation layer without ion-beam assistance should be possible in future PLD-experiments keeping the desired cube texture in thicker films.

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