Search results for "Atomic Force"
showing 10 items of 308 documents
Magnetoelectric coupling driven by inverse magnetostriction in multiferroic BiMn3Mn4O12
2013
By means of neutron powder diffraction, we investigated the effect of the polar Bi$^{3+}$ ion on the magnetic ordering of the Mn$^{3+}$ ions in BiMn$_3$Mn$_4$O$_{12}$, the counterpart with \textit{quadruple} perovskite structure of the \textit{simple} perovskite BiMnO$_3$. The data are consistent with a \textit{noncentrosymmetric} spacegroup $Im$ which contrasts the \textit{centrosymmetric} one $I2/m$ previously reported for the isovalent and isomorphic compound LaMn$_3$Mn$_4$O$_{12}$, which gives evidence of a Bi$^{3+}$-induced polarization of the lattice. At low temperature, the two Mn$^{3+}$ sublattices of the $A'$ and $B$ sites order antiferromagnetically (AFM) in an independent manner …
Some experimental issues of AFM tip blind estimation. The effect of noise and resolution
2006
The convolution of tip shape on sample topography can introduce significant inaccuracy in an AFM image, when the tip radius is comparable to the typical dimension of the sample features to be observed. The blind estimation method allows one to obtain information on the AFM tip through an unknown characterizer sample and thus to perform the deconvolution of the tip shape from an image. When applying the blind estimation method to determine the AFM tip shape, some apparently trivial issues relating to the experimental operating parameters must be taken into account. In this paper, the effects of the operating parameters, e.g., sampling intervals (resolution) and instrumental noise, have been …
Application of atomic and nuclear techniques to the study of inhomogeneities in electrodeposited α-particle sources
2002
Three α-particle sources made by different methods of electrodeposition were analysed using α-particle spectrometry, Rutherford backscattering (RBS), and atomic force microscopy (AFM) on several surface zones. The thickness and homogeneity of these sources was studied using RBS, and the results were analysed jointly with those obtained with α-particle spectrometry and AFM techniques. The comparison of the electrodeposition methods showed that the most homogeneous electrodeposited zones corresponded to the source made with a stirring cathode.
Nanostructuring and strengthening of LiF crystals by swift heavy ions: AFM, XRD and nanoindentation study
2012
Abstract Modifications of the structure and micromechanical properties of LiF crystals under high-fluence irradiation (10 11 –10 13 ions cm −2 ) with swift C, Ti, Au and U ions of the specific energy of 11.1 MeV/u have been studied. In the case of heavy ions (U, Au), the AFM and SEM results reveal the bulk nanostructure consisting of columnar grains with nano-scale dimensions (50–100 nm). For lighter C ions the structure enriched with prismatic dislocation loops has been observed. High-resolution XRD reciprocal space maps for nano-structured LiF expose a mosaic-type structure with low-angle boundaries between grains.
MeV–GeV ion induced dislocation loops in LiF crystals
2014
Abstract Formation of prismatic dislocation loops and evolution of dislocation structure in LiF crystals irradiated with swift 238U and 36S ions of specific energy 11 MeV/u at fluences up to 1013 ions cm−2 has been investigated using chemical etching and AFM. It has been shown that prismatic dislocations are formed in the stage of track overlapping above threshold fluences Φ ≈ 109 U cm−2 and Φ ≈ 1010 S cm−2. The diameter of dislocation loops reaches 600–1000 nm for 238U ions and 200 nm for 36S ions. The dislocations created by 238U ions are arranged in rows along the direction of ion beam, whereas 36S ions create freely distributed dislocation loops each of them being oriented along the ion…
Smooth crack-free targets for nuclear applications produced by molecular plating
2013
The production process of smooth and crack-free targets by means of constant current electrolysis in organic media, commonly known as molecular plating, was optimized. Using a Nd salt, i.e., [Nd(NO3)(3)center dot 6H(2)O], as model electrolyte several constant current density electrolysis experiments were carried out to investigate the effects of different parameters, namely the plating solvent (isopropanol and isobutanol mixed together, pyridine, and N,N-dimethylformamide), the electrolyte concentration (0.11, 0.22, 0.44 mM), the applied current density (0.17, 0.3, 0.7, and 1.3 mA/cm(2)), and the surface roughness of the deposition substrates (12 and 24 nm). Different environments (air and …
Mechanical and electroconductive properties of spatially distributed double stranded DNA arrays on Au (111)
2008
Abstract Conductive AFM was used to investigate electroconductivity through 10 nm long double stranded DNA molecules in mixed monolayers of thioalkylated-DNA and mercaptohexanol (MCH) on Au (111) surface. The distribution of DNA molecules on the surface was analyzed by tapping mode AFM. Measurements performed in lift mode confirmed that the DNA molecules protrude from the surface rather than lie horizontally adsorbed on the interface. The optimal conductivity measurement time, which is shorter than the mechanical relaxation time of oligonucleotide duplexes, was determined. It was concluded that oligonucleotide duplexes have a resistance of the order of ~ 2 Ω ⁎ m at 1 V.
Characterization of the CtsR stress response regulon in Lactobacillus plantarum.
2010
ABSTRACT Lactobacillus plantarum ctsR was characterized. ctsR was found to be cotranscribed with clpC and induced in response to various abiotic stresses. ctsR deletion conferred a heat-sensitive phenotype with peculiar cell morphological features. The transcriptional pattern of putative CtsR regulon genes was examined in the Δ ctsR mutant. Direct CtsR-dependent regulation was demonstrated by DNA-binding assays using recombinant CtsR and the promoters of the ctsR - clpC operon and hsp1 .
Structural, electronic, and electrical properties of an Undoped n-Type CdO thin film with high electron concentration
2014
Transparent conducting metal oxides (TCOs) combine the properties of optical transparency in the visible region with a high electrical conductivity. They are a critical component as the window electrode in liquid crystal and electroluminescent display devices, as well as in many designs of solar cells now under development. Sn-doped In2O3 is currently the most important TCO, but it suffers from some drawbacks. These include the high cost of indium, weak optical absorption in the blue-green region, as well as chemical instability that leads to corrosion phenomena in organic light-emitting devices. Indium tin oxide (ITO) films are also brittle and of relatively low durability. A number of oth…
Formation and evolution of self-organized Au nanorings on indium-tin-oxide surface
2011
This work reports on the formation of Au nanoclusters and on their evolution in nanoring structures on indium-tin-oxide surface by sputtering deposition and annealing processes. The quantification of the characteristics of the nanorings (surface density, depth, height, and width) is performed by atomic force microscopy. The possibility to control these characteristics by tuning annealing temperature and time is demonstrated establishing relations which allow to set the process parameters to obtain nanostructures of desired morphological properties for various technological applications. © 2011 American Institute of Physics.