Nadya Evgenieva Stankova

Nadya Evgenieva Stankova
Bulgarian Academy of Sciences | BAS · Emil Djakov Institute of Electronics

PhD

About

50
Publications
14,687
Reads
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426
Citations
Citations since 2016
31 Research Items
293 Citations
20162017201820192020202120220102030405060
20162017201820192020202120220102030405060
20162017201820192020202120220102030405060
20162017201820192020202120220102030405060
Additional affiliations
May 2006 - June 2007
Università del Salento
Position
  • visiting researcher
September 2001 - November 2015
National Institute for Laser, Plasma and Radiation Physics
Position
  • visiting researcher
January 2000 - present
Bulgarian Academy of Sciences
Position
  • Professor (Assistant), PhD

Publications

Publications (50)
Article
A pump – probe configuration is used to register zerofield level-crossing resonances in Rb vapour contained in a cell with antirelaxation coated walls. The scheme is applied to detect the weak magnetic field generated by a current-carrying micro-wire (metallised track). Such micro-wires can be employed in neural prostheses and hybrid bionic systems...
Article
Full-text available
In this work, the surface modifications are studied of aluminium nitride (AlN) and silicon nitride (Si3N4) ceramics irradiated by nanosecond laser pulses. The laser processing is performed by a Nd:YAG laser system at four wavelengths-266 nm, 355 nm, 532 nm, and 1064 nm. It is found that the average ablation rate per pulse is in the order of few hun...
Article
The aim of our work was to obtain graphene-like phases (defected graphene, graphene oxide and reduced graphene oxide) as fine suspensions by applying pulsed laser ablation (PLA) to microcrystalline graphite suspension in water medium. The fundamental (λ = 1064 nm), second (λ= 532 nm), third (λ= 355 nm) as well as the fourth harmonic (λ= 266 nm) of...
Article
Full-text available
We report on a new approach toward a laser-assisted modification of biocompatible polydimethylsiloxane (PDMS) elastomers relevant to the fabrication of stretchable multielectrode arrays (MEAs) devices for neural interfacing technologies. These applications require high-density electrode packaging to provide a high-resolution integrating system for...
Article
This paper reports on the production of Ag nanoparticles (AgNPs) in a water solution based on a two-phase pulsed laser procedure in view of therapeutic ophthalmological applications requiring AgNPs size of ≤10 nm with a narrow size distribution. Nanoparticles of this size scale are capable of penetrating the complex ocular barriers, thus ensuring e...
Article
Full-text available
Abstract. The method of pulsed laser ablation in liquids is utilized for preparation of composite nanostructures on the basis of TixO2x-1 and Ag. Plates of bulk Ti and Ag immersed in the corresponding liquid serve as targets in the ablation procedure. A nanosecond Nd:YAG pulsed laser is employed as a source of irradiation. Its fundamental wavelengt...
Article
Full-text available
The aim of this work was to obtain graphene-like phases (defected graphene, graphene oxide and reduced graphene oxide) as fine suspensions by applying pulsed laser ablation (PLA) of micro-crystalline graphite suspension in water medium. The fundamental (λ = 1064 nm), second (λ = 532 nm), third (λ = 355 nm) and fourth harmonics (λ = 266 nm) of a Nd:...
Article
Full-text available
In this work, results on a new laser-induced mechanism of microstructures formation on the surface of borosilicate glass are presented. The samples are fabricated by melt quenching method and consist of 50% SiO2, 20% Al2O3, 20% B2O3, 5% CaO, 2% Li2O, 3% MgO (in wt.%). Irradiation at 266 nm delivered by Nd:YAG nanosecond system is used to modify the...
Preprint
This work reports on the production of Ag nanoparticles (AgNPs) in water solution based upon two-phase pulsed laser procedure for ophthalmological therapeutic approaches. In this case, the AgNPs should be less then 10 nm and have a narrow size distribution. Nanoparticles of this sized-scale are capable to penetrate the complex ocular barriers, ensu...
Article
Full-text available
We modified carbon black (CB) with a large surface area (ENSACO 350 GRANULAR) by acetone and further thermal treatment. The pristine and the modified CB were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD) and Raman spectroscopy. The acetone treatment increases the content...
Article
Full-text available
The paper presents results on femtosecond laser irradiation-induced modification of the optical properties of a composite material – gold nanoparticles embedded into a borosilicate glass host. The process is initiated by laser pulses delivered by a Ti:sapphire laser system with pulse duration of 35 fs. The glass samples are prepared by melt quenchi...
Article
This paper describes the luminescence properties of small silver clusters formed by laser treatment of silver-doped borosilicate glass. Using irradiation by a Nd:YAG nanosecond laser system operating at the fourth harmonic wavelength (266 nm), areas are formed in the glass samples that emit bright luminescence peaking at about 600 nm when excited b...
Article
Full-text available
The antibacterial action of Ag-doped Al 2 O 3 nanolayers, deposited by RF reactive magnetron sputtering on hard contact lenses, was established. Synthesis of Ag/Al 2 O 3 protective coatings is necessary for suppressing the infections caused by pathogenic microorganisms following the placement of hard contact lenses. The chemical composition, morpho...
Article
The process of laser radiation-induced formation and decomposition of Ag nanoparticles in glass is studied. Borosilicate glass samples are fabricated by melt quenching method. Silver nitrate is added in the fabrication stage in amount to form final glass samples with compositions of 1, 1.5, 5, and 10 wt% Ag. The fabricated samples are irradiated by...
Article
This work represents results on the response of noble metal-doped borosilicate glass to laser radiation with femto- and nanosecond pulse duration. The material under study is obtained by conventional melt quenching method as samples with noble metal concentration varied up to 10 wt% are fabricated. Optical and morphology changes of the glass sample...
Article
The paper reports on antibacterial and antifungal properties of Ag‐doped Al2O3 nanolayers deposited by RF reactive magnetron sputtering on glass ocular prostheses. The study is provoked by the need of suppressing the infections caused by pathogenic microorganisms following the placement of ocular prostheses. This brings about the idea of forming pr...
Chapter
Medical grade polydimethylsiloxane (PDMS) is widely used in medicine and the production of high-tech devices, such as microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS). In this chapter, results on experimental studies of laser processing of PDMS elastomer by using nanosecond, picosecond or femtosecond lasers, working in...
Article
Noble metal nanoparticle composed glasses attract significant attention due to the unique optical properties that they express in the near UV and visible spectral range. These are related to the high values of the extinction cross section and nonlinear optical characteristics. In this work we study the ability of laser irradiation to induce modific...
Poster
Full-text available
The research is focused on fundamental study of processes and effects of interaction of short and ultra-short laser irradiation with optical transparent nanocomposite biocompatible polymers. Laser generation from ultraviolet to near infrared regions of the spectrum is applied. The high optical transparency of the biopolymers in this range and the r...
Article
Full-text available
We present results on laser-induced color changes in gold- and silver-doped glass. The doped borosilicate glass was prepared by conventional melt quenching. The study was focused on the change of the optical properties after irradiation of the glass by femtosecond laser pulses. Under certain conditions, the laser radiation induces defects associate...
Article
In this work the effects of laser radiation and annealing process on the change of the optical properties of gold doped borosilicate glass are presented. The glass is fabricated by conventional melt quenching method as samples with three different concentrations of gold are produced. The laser irradiation is performed by a Nd:YAG system that genera...
Article
Full-text available
We present results on laser-assisted formation of two- and three-dimensional structures comprised of gold nanoparticles in glass. The sample material was gold-ion-doped borosilicate glass prepared by conventional melt quenching. The nanoparticle growth technique consisted of two steps – laser-induced defect formation and annealing. The first step w...
Poster
PDMS was structured by Nd:YAG laser for creating functionalized surfaces which could be used to build up microelectrode arrays.
Article
Full-text available
The medical-grade polydimethylsiloxane (PDMS) elastomer is a widely used biomaterial in medicine and for preparation of high-tech devices because of its remarkable properties. In this work, we present the experimental results on drilling holes on the PDMS surface by using ultraviolet, visible or near-infrared ns-laser pulses and on studying the cha...
Article
Medical grade polydimethylsiloxane (PDMS) elastomer is a biomaterial widely used in medicine and high-tech devices, e.g. MEMS and NEMS. In this work, we report an experimental investigation on femtosecond laser processing of PDMS-elastomer with near infrared (NIR), visible (VIS) and ultraviolet (UV) pulses. High definition trenches are produced by...
Article
Full-text available
This article presents experimental investigations of effects of the process parameters on the medical grade polydimethylsiloxane (PDMS) elastomer processed by laser source with irradiation at UV (266 and 355 nm), VIS (532 nm) and NIR (1064 nm). Systematic experiments are done to characterize how the laser beam parameters (wavelength, fluence, and n...
Article
Medical grade polydimethylsiloxane (PDMS) elastomer is a widely used biomaterial as encapsulation and/or as substrate insulator carrier for long term neural implants because of its remarkable properties. Femtosecond (λ = 263 and 527 nm) and nanosecond (266 and 532 nm) laser processing of PDMS-elastomer surface, in air, is investigated. The influenc...
Article
Full-text available
The paper presents a study of a physical method for fabrication of two-dimensional (2D) arrays composed of multi-component nanoparticles on a dielectric substrate. The method consists of two steps. In the first one, thin films composed of different metals are deposited by a classical PLD technique by using targets consisting of sections of differen...
Article
Full-text available
We review the current status of metallic photocathodes based on thin films prepared by pulsed laser deposition (PLD) and we explore ways to improve the performance of these devices. PLD seems to be a very efficient and suitable technique for producing adherent and uniform thin films. Time-resolved mass spectrometric investigations definitively sugg...
Article
Pulsed laser deposition technique was used to fabricate successfully nanostructured optical waveguide films of TiO2 and WO3 − x for gas-sensing applications. High-quality mode spectra, consisting of well-defined bright mode lines were observed in the samples with smooth surface. Films' structural, morphological and optical properties as well as the...
Article
The evolution of the crystal, the microstructural and the optical properties of pulsed-laser deposited TiO2 films, investigated by X-ray diffraction, atomic force microscopy, scanning electron microscopy, optical transmittance and m-line spectroscopy measurements are reported. The samples were grown on (0 0 1) SiO2 substrates at temperatures from 2...
Article
Tin oxide (SnO 2) thin films were grown on Si (1 0 0) substrates using pulsed laser deposition (PLD) in O 2 gas ambient (10 Pa) and at different substrate temperatures (RT, 150, 300 and 400 1C). The influence of the substrate temperature on the structural and morphological properties of the films was investigated using X-ray diffraction (XRD), atom...
Article
ZnO thin films were grown on Si(100) substrates using pulsed laser deposition in O2 gas ambient (10Pa) and at different substrate temperatures (25, 150, 300 and 400°C). The influence of the substrate temperature on the structural and morphological properties of the films was investigated using XRD, AFM and SEM. At substrate temperature of T=150°C,...
Article
In this work the optical and the gas sensing properties of thick TiO2 waveguide films, produced by pulsed laser deposition, were investigated by m-line spectroscopy. The films were deposited on (0 0 1) SiO2 substrates at temperature of 100 °C. The thickness of the films was measured to be in the range from 650 to 1900 nm and the roughness increases...
Article
Highly textured thin (0 0 1) tungsten trioxide (WO3) films have been deposited on (0 0 1) SiO2 substrates by XeCl excimer laser ablation of ceramic targets. The influence of the oxygen pressure and substrate temperature on the composition, crystallinity and optical properties of the films has been studied. The films were grown at pressures of 1–25...
Article
Thin indium oxide (In2O3) films were grown on (001) SiO2 by pulsed laser deposition technique at oxygen pressure from 1 to 20 Pa and substrate temperature between 100 and 500 degrees C from ceramic targets. The structural and optical properties of the films were investigated as a function of the growth conditions - oxygen pressure and substrate tem...
Article
Thin TiO2 films were grown on (001) SiO2 substrates using excimer KrF laser ablation of ceramic targets. The influence of deposition temperatures at fixed oxygen pressure of 10 Pa on the crystal and optical properties of the films was investigated. Structural characterisation by X-ray diffraction and Raman spectroscopy shows preferential crystalliz...
Article
LiNbO3 thin films were synthesized by pulsed KrF* (λ=248 nm, τFWHM∼-20 ns, v = 1 Hz) laser ablation of Li-rich ceramic targets on (001) Al2O3 substrates. The crystalline state and composition of the as-grown films were studied by X-ray diffraction (XRD), Rutherford backscattering spectroscopy (RBS) and nuclear reaction analyses (NRA). The laser flu...
Article
LiNbO3 thin films were grown on (100) MgO substrates by pulsed KrF* (lambda=248 nn, tau(FWHM)similar to20 ns, v=1 Hz) laser ablation of Li-rich ceramic targets in low pressure oxygen atmosphere. The substrates were heated during the thin film deposition process at 550 degreesC. The as-grown thin films were submitted to a heat treatment in oxygen at...

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Projects

Projects (2)
Archived project
Main research goals in the project: - development of a method for laser induced formation of 3D noble metal nanoparticle ensembles in glass materials; - understanding the role of the material composition and experimental conditions of laser and heat treatment on the spatial properties of the structures; - fabrication of 3D noble metal nanoparticle structures and description of their optical properties. Bulgarian Academy of Sciences: Institute of Electronics, Institute of Solid State Physics, Institute of General and Inorganic Chemistry
Project
Development of new materials for their application as microelectrode arrays (MEAs) devices in neural interface technologies for monitor and/or stimulation of neural activity, implanted in soft tissue - neuroprostheses: fabrication of well-defined trenches by direct laser micro-structuring and activating the surface of biocompatible polymer polydimethylsiloxane (PDMS) and subsequent effective electroless chemical metallization with Ni and Pt of the treated areas.