I. Aulika

I. Aulika
Independent Researcher · Thin Films Laboratory

PhD

About

54
Publications
7,437
Reads
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305
Citations
Introduction
Currently I'm working in Camart2 project (www.camart2.eu) with the aim to broaden the scientific and industrial network of the ISSP UL, increase the number of public and private funded R&D projects in the institute, open new collaboration opportunities for the ISSP scientific staff. Research activities: innovative materials for electronics and photonics, new horizons of spectroscopic tools.
Additional affiliations
April 2018 - present
Institute of Solid State Physics, University of Latvia
Position
  • Project Manager
Description
  • New R&D idea development; Assistance in project writing and evaluation; New industrial and academic partner search and involvement; Local contact point in proposal writing and execution, and representative for ISSP ULs’ industry collaboration platform Materize (www.materize.com) in Italy, France, Spain and Switzerland; Lecture development for MsC physics’ students on applications of piezoelectric material; Spectroscopic ellipsometry for material research and industry.
March 2012 - February 2017
Eltek Group
Position
  • Scientific collaborator
Description
  • Research and development of biological sensors: characterization & fabrication of microsystems for diagnostics & sensors (cell & bacteria sensing & counting). Responsible of FESEM analyses.
January 2010 - February 2012
Istituto Italiano di Tecnologia
Position
  • Scientific collaborator, Post-doctoral fellow
Description
  • Defined the layout & completed a new laboratory for characterization & development of nanoscale structures & devices; Responsible of dual-beam FIB-FESEM laboratory; Research on the nanogap-based sensors, micro/nano probing & microprocessing.
Education
October 2004 - December 2008
University of Latvia
Field of study
  • Optical depth profile and phase transitions investigation of NaNbO3 and Pb(Zr,Ti)O3 thin films
June 2002 - June 2004
University of Latvia
Field of study
  • Optical studies of ferroelectric heterostructures by ellipsometry and spectral reflectometry
June 1998 - June 2002
University of Latvia
Field of study
  • Determination of thickness and refractive index of thin films by optical reflectometry and ellipsometry

Publications

Publications (54)
Preprint
Full-text available
In this work, single layer 3,3′-Di(9H-carbazol-9-yl)-1,1′-biphenyl (mCBP), tris(4-carbazoyl-9-ylphenyl)amine (TCTA) and 4,6-Bis(3,5-di-3-pyridinylphenyl)-2-methylpyrimidine (B3PymPm) organic thin films optical properties were investigated by spectroscopic ellipsometry and spectrophotometer. Films were fabricated by thermal evaporation on glass, qua...
Article
Full-text available
We investigate the effective oxidation state and local environment of yttrium in photochromic YHO thin film structures produced by e-beam evaporation, along with their chemical structure and optical properties. Transmission electron microscopy images reveal the oxidized yttrium hydride thin film sample exhibiting a three-layered structure. X-ray ph...
Article
Full-text available
WO3/Cu/WO3 coatings are transparent electrodes, but conductivity and transmittance have been observed to decrease with time. This paper reports the improved stability of WO3/Cu/WO3 coatings deposited by magnetron sputtering on glass and polyethylene terephthalate substrates. The stability issues due to Cu oxidation and migration can be addressed by...
Preprint
Full-text available
An experimental investigation was conducted to explore spectroscopic and structural characterization of semiconducting yttrium oxide thin film deposited at 623 K (+/- 5K) utilizing reactive pulsed direct current magnetron sputtering. Based on the results obtained from both x-ray diffraction and transmission electron microscope measurements, yttrium...
Article
Full-text available
An experimental investigation was conducted to explore spectroscopic and structural characterization of semiconducting yttrium oxide thin film deposited at 623 K (± 5K) utilizing reactive pulsed direct current magnetron sputtering. Based on the results obtained from both x-ray diffraction and transmission electron microscope measurements, yttrium m...
Preprint
Full-text available
Crystalline wurtzite zinc oxide (w-ZnO) can be used as a wide band gap semiconductor for light emitting devices and for transparent or high temperature electronics. The use of amorphous zinc oxide (a-ZnO) can be an advantage in these applications. In this paper we report on X-ray amorphous a-ZnOx thin films (~500 nm) deposited at cryogenic temperat...
Preprint
Full-text available
The synthesis of the photochromic YHO films is based on the oxidation of deposited yttrium hydride in ambient conditions. The actual state of the films during the deposition process, which is influenced by the deposition pressure and the oxidation caused by the residual gases, is not completely known. We report on the YHxOy thin films deposited by...
Article
Full-text available
The synthesis of the photochromic YHO films is based on the oxidation of deposited yttrium hydride in ambient conditions. The actual state of the films during the deposition process, which is influenced by the deposition pressure and the oxidation caused by the residual gases, is not completely known. We report on the YHxOy thin films deposited by...
Article
Full-text available
Wurtzite Zn1-xMgxO epilayers (x=0, 0.26, 0.44, 0.49, 0.66) grown by the plasma-assisted molecular beam epitaxy on ScAlMgO4 substrate were characterized using the methods of optical spectroscopy: spectroscopic ellipsometry (SE), optical absorption (OA), and photoluminescence (PL). The complex dielectric function in the spectral range of 210 to 1690...
Preprint
Full-text available
Herein, the concept of point of darkness based on polarized light phase difference and absorption of light is demonstrated by simulations using low refractive index and extinction coefficient semiconductor and dielectric, and high refractive index nonoxidizing metal multilayer thin film structures. Several multilayer sensor configurations show grea...
Poster
Full-text available
Phase-sensitive and zero-light reflection can be designed not only for single wavelength and single incident angles, but also for broad spectral regions and for variety of incident angles using multilayer thin film structures with low refractive index n semiconductor and dielectric materials, and high n metals.
Preprint
The synthesis of the photochromic YHO films is based on the oxidation of deposited yttrium hydride in ambient conditions. The actual state of the films during the deposition process, which is influenced by the deposition pressure and the oxidation caused by the residual gases, is not completely known. We report on the YHxOy thin films deposited by...
Presentation
Full-text available
The synthesis of the photochromic YHO films is based on the oxidation of deposited yttrium hydride in ambient conditions. The actual state of the films during the deposition process, which is influenced by the deposition pressure and the oxidation caused by the residual gases, is not completely known. We report on the YHxOy thin films deposited by...
Presentation
Full-text available
The Tauc’s method [1] is a much-preferred optical band gap (OBG) evaluate method for amorphous (or glassy) materials. However, regardless its clear and simple purpose, it has been routinely and incorrectly applied to study crystalline semiconductors and dielectrics. In Tauc relation the density of electron states is close to the VB and CB extrema...
Article
Full-text available
Here the concept of point of darkness based on polarized light phase difference and absorption of light is demonstrated by simulations using low refractive index and extinction coefficient semiconductor and dielectric, and high refractive index non-oxidizing metal multilayer thin film structures. Several multilayer sensor configurations show great...
Article
Full-text available
Crystalline wurtzite zinc oxide (w-ZnO) can be used as a wide bandgap semiconductor for light emitting devices and transparent or high temperature electronics. The use of amorphous zinc oxide (a-ZnO) can be an advantage in these applications. In this paper, we report on x-ray amorphous a-ZnO x thin films (∼500 nm) deposited at cryogenic temperature...
Article
Laser induced photo-thermal resistance response (PTRR) of polyisoprene/nanographite (PN) composites was studied. An inverse character of photoresistance in comparison to semiconductor-like materials was observed: electrical resistance of the PN composite increases when the intensity of the laser radiation is increased. The observed response can be...
Article
This study revealed the influence of crystallisation processes on the homogeneity of the sol–gel PbZr0·52Ti0·48O3 thin films, allowing identification and further optimisation of thin film performance. Crystallisation processes determine the optical gradient appearance, irrespective of the chemical solvents used in this work. X-ray diffraction analy...
Article
Full-text available
The main topic of this paper is the study of polyisoprene-multi wall carbon nanotubes (PiMWCNT) composite’s electrical conductivity and volatile organic compound sensing properties with respect to type of multi wall carbon nanotubes used. Electrical percolation parameters like percolation threshold and critical exponent of produced composites are d...
Article
This paper presents a very low-complexity all-digital IR-UWB transmitter that can generate pulses in the band 0-5 GHz, requiring a silicon area lower than a PAD for signal I/O. The transmitter, suited to non-standardized low data rate applications, is prototyped in a 130 nm RFCMOS technology and includes analog control signals for frequency and ban...
Article
Full-text available
We present dynamic mechanical analysis (DMA) and thermomechanical analysis (TMA) measurements of a new type of polyurea elastomer nanocomposites based on inorganic MoS2 nanotubes and Mo 6 S 2 I 8 nanowires. The addition of a small amount of nanoparticles (<1 wt-%) leads to an increase of the glass transition temperature T g as compared to the pure...
Article
Full-text available
We report on the preparation of ferroelectric polymeric nanowires through hard-templating strategy. Wet-impregnation of poly(vinylidene fluoride) (PVDF) and its copolymer poly(vinylidene fluoride-tri fluoro ethylene) [P(VDF TrFE)] was performed into commercially available porous Anodic Alumina Membrane (AAM). The polymeric nanowires show a diameter...
Article
Full-text available
Thermal expansion and electromechanical properties are studied for compositions Na1/2Bi1/2TiO3-SrTiO3-PbTiO3, belonging to various locations in the phase diagram. The main purpose of the studies is to extend the range of physical properties, which characterise the relaxor state and could be used for comparison with other relaxors. Possibility to ev...
Article
Comparative studies of ZnO crystalline and amorphous thin films and nanocrystalline powders are reported. The UV-visible optical spectra were analyzed with special attention paid to the direct optical bandgap. Atmospheric radio-frequency barrier torch discharge and pulsed hollow cathode sputtering techniques for the film fabrication were used. For...
Article
Full-text available
Investigation using a variable angle spectroscopic ellipsometer revealed the influence of sample preparation conditions on sol–gel (PZT ) thin-film homogeneity that allows identification and further optimization of thin-film performance. Separate crystallization of the layers determined the optical gradient appearance, irrespective of the chemi...
Article
In this work a spectroscopic ellipsometry was applied to the thermo-optical investigations of sodium niobate NaNbO3 (NN) thin films at the wide temperature range of 5–820 K. The temperature dependence of complex refractive index dispersions and optical bang energy of the direct allowed electron transitions were evaluated. Additionally dynamic scans...
Data
Investigation using a variable angle spectroscopic ellipsometer revealed the influence of sample preparation conditions on sol–gel PbZr0.52Ti0.48O3 (PZT 52/48) thin-film homogeneity that allows identification and further optimization of thin-film performance. Separate crystallization of the layers determined the optical gradient appearance, irrespe...
Article
Full-text available
The possibilities of in situ spectroscopic ellipsometry applied to phase transitions investigation in oxide thin films and crystals are examined in this work, along with the use of various parameters calculated from ellipsometric data (band gap energy Eg , refractive index n and surface roughness) together with the directly measured main ellipsomet...
Article
Role of a La on the nature of phase transition in the PLZT x/85/15 is compared with the PLZT compositions of lower Zr/Ti ratio. Thermal dependence of the dielectric permittivity, thermal expansion and elastic modulus reveal sequential transfer from macroscopic ferroelectric to antiferroelectric and nonpolar state, if La concentration is increased....
Article
Ellipsometric studies of the optical gradient of thin films were performed in the photon energy range of . Effective values of the complex refractive index and thickness nonuniformity, roughness, and depth profile of the real part of the refractive index were evaluated. An increase of the refractive index with increasing of the sample thickness...
Article
Structural and optical properties of Ba0.8Sr0.2TiO3(BST) ferroelectric thin films, deposited by the pulsed laser ablation (PLD) technique on Si/SiO2/Ti/Pt, Si/SrRuO3 and Si substrates, were performed by X-ray diffraction, micro Raman, atomic force microscopy (AFM), and optical reflectometry measurements. Temperature dependences of the Raman spectru...
Article
Full-text available
Thermo-optical studies of sodium niobate NaNbO3 (NN) thin films, deposited by the pulsed laser ablation technique on Si/SrRuO3 substrates, were performed by spectroscopic ellipsometry in the temperature range 300-550°C. Optical constants at the room temperature were measured in the spectral range 250-1000 nm. Substantial changes in the refractive i...
Article
Full-text available
Sodium niobate NaNbO3 thin films were deposited by the pulsed laser ablation (PLD) technique on Si/SiO2/Ti/Pt/SrRuO3 and Si/SrRuO3 substrates. The structural and optical investiga- tions were performed by X-Ray, micro Raman, ellipsometry and atomic force microscopy (AFM). The Raman spectra of NN have been studied at temperatures from 80 up to 743K...
Article
Our recent achievements in design, processing and studies of physical properties of polymer-nanostmctured carbon composites (PNCC) as prospective strain sensor and gas sensor materials are presented. Mechanical, electrical and gas sorption properties have been investigated. Electrically conductive atomic force microscopy (EC AFM), positron annihila...
Article
The alternating-current (AC) properties, which include conductivity and dielectric permittivity, of elastomer-carbon nanocomposites were investigated using inter-cluster polarization model. The sample was synthesized by rolling highly structured extra-conductive carbon black in the polyisoprene (PI) matrix. The model was found to be dominated in th...
Article
Irradiation effects on highly oriented antiferroelectric PbZrO3 and ferroelectric Pb0.92La0.08(Zr0.65Ti0.35)O3 thin films are investigated being exposed to neutron irradiation up to fluence 2*1022 m−2. The higher resistance of antiferroelectric PbZrO3 thin films as compared to ferroelectric heterostructures to large fluences of neutron irradiation...
Article
Full-text available
Time-dependent Ginsburg-Landau theory is combined with Langevin, Fokker-Planck and nonstationary Schrödinger equation techniques to model impact of thermal noise in kinetics of ferroelectric polarization. A real space/real time method based on Cayley's form and Suzuki's decomposition is implemented for numerically simulating both relaxation of pola...
Article
Full-text available
A method of analyzing variable-angle null-ellipsometry and reflectometry measurement data is proposed for barium titanate BaTiO3 (BT), lead zirconate titanate PbZr0,47Ti0,53O3 (PZT) and lead magnesium niobate Pb(Mn0,33Nb0,67)O3 (PMN) thin films grown on Si/SiO2/Ti/Pt, Si/TiO2/Pt, substrates by laser ablation, sol-gel and rf sputtering. The refracti...
Article
Full-text available
Lead zirconate PbZrO3 (PZ) and PbZr0.53Ti0.47O3 (PZT) sol-gel films with a thickness of up to 1.5 mum were deposited on TiO2/Pt/TiO2/SiO2/Si substrates by spin coating technique and heterostructures of the same composition as well as on Pb0.92La0.08 (Zr0.65Ti0.35)O3 (PLZT-8) (with a thickness of 0.4 mum) were pulse laser deposited (PLD) on Pt/Ti/Si...
Article
Full-text available
The crystallographic features of binary system Pb(LuNb)O3-PbTiO3 (PLuNT) including the morphotropic phase boundary (MPB) region between tetragonal P4mm and pseudo-monoclinic M phases are reported and discussed with respect to dielectric, polarization and electromechanical characteristics. Non-isovalent doping of PLuNT in the Pb sublattice according...
Article
Full-text available
After investigations on sputtered nanocrystalline ferroelectric Pb 0.76 Ca 0.24 TiO 3 (PTC) films and nanocrystalline relaxor films, namely Pb(Sc 0.5 Ta 0.5 )O 3 (PST), Pb(Sc 0.5 Nb 0.5 )O 3 (PSN) and Pb(Mg 1/3 Nb 2/3 )O 3 (PMN) we started to investigate effects in multilayers of nanocrystalline ferroelectric and relaxor films. The increasing size...

Questions

Questions (2)
Question
Institute of Solids State Physics, University of Latvia is going to make numerous Post Doc applications both national and Marie Curie Individual Fellowships. Please, look in the attached PDF file details and contact me in case of interest.
Question
I’m evaluating the importance of a real-time monitoring of the cell cultures conditions for wound-healing, chemotaxis-migration, pharmaceutical development, cancer, proliferation, apoptosis and other applications. I have prepared the survey to evaluate the characteristics of an instrument permitting such in-situ microbiological studies.
I would appreciate very much if you could dedicate 5 - 10 minutes filling out the questionnaire, giving an important feedback in development of high tech instrumentation for microbiology.

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