Search results for "substrate"
showing 10 items of 1018 documents
Growth mechanism and transport properties of thin La0.67Ca0.33MnO3 films
1999
Abstract We prepared thin films of La 0.67 Ca 0.33 MnO 3 on different substrates with DC sputtering. The measured transport and magnetic properties could be explained by a lattice mismatch induced by the substrate. Hall effect measurements showed a holelike charge carrier density n * h = 1.3 per unit cell below T C . The magnetoresistance results from an increase of the mobility of the charge carriers in magnetic field.
Bilayer graded Al/B4C/rice husk ash composite: Wettability behavior, thermo-mechanical, and electrical properties
2018
In this study, wettability behavior of B4C substrate as well as B4C/crystalline rice husk ash and B4C/amorphous rice husk ash substrates with two aluminum alloys were studied. The electrical resistivity, thermal expansion coefficients, and thermal diffusivity of bilayer Al/B4C/rice husk ash composite fabricated by one-step pressureless infiltration were measured and the obtained data were systemically analyzed using the Taguchi method and analysis of variance. Boron carbide substrates after addition of amorphous or crystalline rice husk ash display good wettability with molten aluminum alloys. The results show that, electrical resistivity of Al/B4C/rice husk ash composites is mainly influe…
FINITE DIFFERENCE METHOD-BASED SIMULATION OF TEMPERATURE FIELDS FOR APPLICATION TO ORTHOGONAL CUTTING WITH COATED TOOLS
2005
ABSTRACT A finite difference method was proposed to model the effect of a variety of tool coatings on the magnitude and distribution of temperatures through the tool-chip contact region and the coating/substrate boundaries. For each workpiece-tool pair tested the intensity of uniformly distributed heat flux and relevant analytically obtained values of the heat partition coefficient were assumed to change with variations of cutting speed and the corresponding friction. In this case the simulation of an orthogonal machining of AISI 1045 steel was performed using special computing algorithm with elementary balances of induced energies (MBE). It is concluded that the temperature contours obtain…
Structural and spectral properties of ZnO nanorods by wet chemical method for hybrid solar cells applications
2015
Abstract The synthesis of ZnO nanorods on transparent conducting oxides, Al doped ZnO seed layer on glass substrate (AZO) and indium tin oxide substrate (ITO) by using zinc nitrate hexahydrate (Zn (NO3)2·6H2O) and hexamethylenetetramine (HMT, (CH2)6N4 as raw materials is presented. The ZnO seed layer was fabricated by depositing an Al-doped ZnO thin film on glass substrate by sputtering. The effect of seeding on (AZO) and (ITO) substrate by using the wet chemical route growth of ZnO nanorods was investigated. The synthesized nanostructures of ZnO were characterized by X-ray diffraction (XRD), UV–vis absorption spectroscopy, scanning electron microscopy (SEM) and high-resolution transmission…
Structural and Magnetic Properties of Epitaxial Ni<sub>2</sub>MnGa Thin Films
2009
We report on the preparation and investigation of epitaxial thin films of the magnetic shape memory alloy Ni2MnGa. For samples close to the stoichiometric composition we find that the phase transformation temperature is affected by the crystallographic orientation. Changes in the crystal structure due to the transformation are observed using temperature-dependent X-ray diffraction. Films with higher manganese content are in the martensitic state at room temperature. Those samples on Al2O3(11-20) reveal the 7-layered orthorhombic structure that allows strains up to 10 %. To avoid blocking of magnetostrictive effects by the substrate, free-standing films are prepared using water-soluble NaCl(…
Reactive sputtering of nanostructured multilayer coatings and their tribological properties
1999
Abstract The present study describes and reports on reactive sputtering of nanostructured multilayer coatings. A 3 μm coating for instance may contain up to a few thousand bilayers of two different film materials, and in order to achieve this, a substrate holder rotates through two different sputtering zones in an Alcatel SC 650 sputtering equipment with metal and carbon cathodes operating concurrently in the so-called side-by-side configuration. In reactive sputtering of nitrides, reactive nitrogen was controlled very accurately in order to establish controllable points on a total sputtering pressure versus nitrogen flow curve. Nanostructured multilayer coatings of the type MeN/C–N were de…
Self-assembly of amphiphilic imidazolium-based hexa-peri-hexabenzo-coronenes into fibreous aggregates
2007
Imidazolium-based amphiphilic hexa-peri-hexabenzocoronenes were synthesized and shown to undergo ordered columnar self-assembly in solid-state as well as in solution to yield defined nanofibers upon solution drop casting onto solid substrate.
On-Surfaces Synthesis on Insulating Substrates
2016
On-surface synthesis has attracted great attention in recent years due to its promising potential for creating functional structures on surfaces. An important aspect of on-surface synthesis is the capability to arrive at covalently linked thermally stable structures that offer the possibility for application even in harsh environments outside ultra-high vacuum conditions. Additionally, covalent linking allows for fabricating conjugated structures with superior electron transport properties. Especially, the latter is of tremendous interest when considering future applications in the field of molecular electronics. Having molecular electronics applications in mind explains the need for decoup…
Electrochemical deposition of polypyrrole nanolayers on discontinuous ultrathin gold films.
2008
Ultrathin layers of polypyrrole (PPy) were electrochemically grown between microelectrodes on a $Si/SiO_2$ substrate. Conducting nanolayers of PPy are directly grown onto ultrathin discontinuous gold (Au) film between the microelectrodes, with thicknesses in the range 10–100 nm. The system therefore forms a novel (PPy/Au) nanocomposite conductor. Atomic force microscopy (AFM) imaging and conductivity measurements indicate that at all thicknesses a relatively uniform film is formed but with significant roughness that reflects the roughness of the metallic island layer. In PPy/Au films with thickness $\sim 10 nm$, the small barriers around the gold islands dominate the conduction, and as the …
DNA-Assisted Molecular Lithography
2018
During the past decade, DNA origami has become a popular method to build custom two- (2D) and three-dimensional (3D) DNA nanostructures. These programmable structures could further serve as templates for accurate nanoscale patterning, and therefore they could find uses in various biotechnological applications. However, to transfer the spatial information of DNA origami to metal nanostructures has been limited to either direct nanoparticle-based patterning or chemical growth of metallic seed particles that are attached to the DNA objects. Here, we present an alternative way by combining DNA origami with conventional lithography techniques. With this DNA-assisted lithography (DALI) method, we…