Activity of All-Russian Research Institute of Physical-Technical and Radio-Technical Measurements (VNIIFTRI) in the sphere of physicochemical measurements

This article presents the description, metrological characteristics and application of State primary standards developed at the All-Russian Research Institute of Physicol-Technical and Radio-Technical Measurements (VNIIFTRI). These include the state primary standards for pH and pX in aqueous solutions, units of the dispersed parameters of aerosols, suspensions and powdery materials, units of the mass fraction and mass (molar) concentration of inorganic components in aqueous solutions based on gravimetric and spectral methods of analysis. In addition, the article discusses R&D projects that are currently being realized at VNIIFTRI, including the production of standard-titres and buffer solutions for pH-metry, as well as working standards for assessing the activity of Na+, K+, F- , Cl- , Br- , I- , NO3- (pX) ions in aqueous media

Participation of VNIIFTRI in international comparisons in thefield of physical-chemical measurements

This paper considers the participation of FSUE «VNIIFTRI» in international comparisons: in the field of physicalchemical measurements, particularly in pH-metry and ionometry (pX); in the sphere of measuring inorganic components in various matrices. Measurement and calibration capabilities are presented – CMC lines in the BIPM database

Azimuthal and polar anchoring energies of aligning layers structured by nonlinear laser lithography

In spite of the fact that there are different techniques in the creation of the high-quality liquid crystals (LCs) alignment by means of various surfaces, the azimuthal and polar anchoring energies as well as the pre-tilt angle are important parameters to all of them. Here, the modified by a certain manner aligning layers, previously formed by nonlinear laser lithography (NLL), having high-quality nano-periodic grooves on Ti surfaces, recently proposed for LC alignment was studied. The change of the scanning speed of NLL in the process of nano-structured Ti surfaces and their further modification by means of ITO-coating, and deposition of polyimide film has enabled different aligning layers, whose main characteristics, namely azimuthal and polar anchoring energies, were measured. For the modified aligning layers, the dependencies of the twist and pre-tilt angles for LC cells filled by nematic E7 ({\Delta}{\epsilon} > 0) and MLC-6609 ({\Delta}{\epsilon} < 0) were obtained. Also the contact angle for droplets of isotropic liquid (glycerol), and nematic LCs was measured for the various values of the scanning speed during the laser processing.Comment: 49 pages, 18 figure

Cherenkov radiation of spin waves by ultra-fast moving magnetic flux quanta

Despite theoretical predictions for a Cherenkov-type radiation of spin waves (magnons) by various propagating magnetic perturbations, fast-enough moving magnetic field stimuli have not been available so far. Here, we experimentally realize the Cherenkov radiation of spin waves in a Co-Fe magnonic conduit by fast-moving (>1 km/s) magnetic flux quanta (Abrikosov vortices) in an adjacent Nb-C superconducting strip. The radiation is evidenced by the microwave detection of spin waves propagating a distance of 2 micrometers from the superconductor and it is accompanied by a magnon Shapiro step in its current-voltage curve. The spin-wave excitation is unidirectional and monochromatic, with sub-40 nm wavelengths determined by the period of the vortex lattice. The phase-locking of the vortex lattice with the excited spin wave limits the vortex velocity and reduces the dissipation in the superconductor.Comment: 11 pages, 5 page

Moving flux quanta cool superconductors by a microwave breath

Almost any use of a superconductor implies a nonequilibrium state. Remarkably, the non-equilibrium states induced by a microwave stimulus and the dynamics of magnetic flux quanta (Abrikosov vortices) can give rise to strikingly contrary effects: A sufficiently high-power electromagnetic field of GHz frequency can stimulate superconductivity, whereas fast vortex motion can trigger an instability abruptly quenching the superconducting state. Here, we advance or delay such dynamical quenching of the vortex state in Nb thin films by tuning the power and frequency of the microwave ac stimulus added to a dc bias current. The experimental findings are supported by time-dependent Ginzburg-Landau simulations and they can be explained qualitatively based on a model of "breathing mobile hot spots", implying a competition of heating and cooling of quasiparticles along the trajectories of moving fluxons whose core sizes vary in time. In addition, we demonstrate universality of the stimulation effect on the thermodynamic and transport properties of type II superconductors.Comment: 11 pages. 7 figure