Competing length scales and 2D versus 3D dimensionality in relatively thick superconducting NbN films.

Magneto-transport characteristics of 2D and 3D superconducting layers, in particular, temperature and angular dependences of the upper critical field H, are usually considered to be fundamentally different. In the work, using non-local resistance measurements at temperatures near the normal-to-superconducting transition, we probed an effective dimensionality of nm-thick NbN films. It was found that in relatively thick NbN layers, the thicknesses of which varied from 50 to 100 nm, the temperature effect on H certainly pointed to the three-dimensionality of the samples, while the angular dependence of H revealed behavior typical for 2D samples.

Fluoride-free synthesis of anodic TiO nanotube layers: a promising environmentally friendly method for efficient photocatalysts.

TiO nanotube (TNT) layers are generally prepared in fluoride-based electrolytes electrochemical anodization that relies on the field-assisted dissolution of Ti metal forming nanoporous/nanotubular structures. However, the usage of fluoride ions is considered hazardous to the environment. Therefore, we present an environmentally friendly synthesis and application of TNT layers prepared in fluoride-free nitrate-based electrolytes.

Remarkable Improvement in Hydrogen Sensing Characteristics with Pt/TiO Interface Control.

Owing to their excellent hydrogen surface susceptibility, TiO thin films have been proven worthy of sensing hydrogen. However, these sensors work best at temperatures of 150-400 °C, with poor selectivity and a low response at room temperature. In this context, the novelty of this paper includes an investigation of the critical role of electrode fabrication that is found to significantly define the surface as well as the performance of a sensor.

Surface charge and carbon contamination on an electron-beam-irradiated hydroxyapatite thin film investigated by photoluminescence and phase imaging in atomic force microscopy.

The surface properties of hydroxyapatite, including electric charge, can influence the biological response, tissue compatibility, and adhesion of biological cells and biomolecules. Results reported here help in understanding this influence by creating charged domains on hydroxyapatite thin films deposited on silicon using electron beam irradiation and investigating their shape, properties, and carbon contamination for different doses of incident injected charge by two methods. Photoluminescence laser scanning microscopy was used to image electrostatic charge trapped at pre-existing and irradiation-induced defects within these domains, while phase imaging in atomic force microscopy was used to image the carbon contamination.

Directly created electrostatic micro-domains on hydroxyapatite: probing with a Kelvin Force probe and a protein.

Micro-domains of modified surface potential (SP) were created on hydroxyapatite films by direct patterning by mid-energy focused electron beam, typically available as a microprobe of Scanning Electron Microscopes. The SP distribution of these patterns has been studied on sub-micrometer scale by the Kelvin Probe Force Microscopy method as well as lysozyme adsorption. Since the lysozyme is positively charged at physiological pH, it allows us to track positively and negatively charged areas of the SP patterns.