| Topic title |
Possible scientific supervisors |
Source of funding |
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Bismuth titanate thin film synthesis and characterization
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doc. dr. Aleksandras ILJINAS |
state-funded |
Research Topic Summary.
Complex and expensive technology of active ferroelectric film and many not solved physical-technological problems are main reason for further study. The proposing technique to synthesize active ferroelectric films bismuth titanate by using reactive magnetron layer-by-layer deposition on 300-600 oC substrate temperature is the basic idea of this investigation. Original equipment, constructed at KTU, Department of Physics will be used to synthesize high stoichiometry thin films. The main goal of this work is to synthesis the properties of active ferroelectric bismuth titanate with impurities layer and to perform an investigations, which will allow to obtain the best characteristics. The specific piezoelectric, pyroelectric and electrocaloric properties of designed ferroelectric films also will be investigated in this work.
The aim of the study
To investigate bismuth titanate oxide films of growth using reactive layer-by-layer magnetron sputtering. To investigate the structure of thin layers, surface morphology, ferroelectric and ferromagnetic properties.
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| Chemical etching of gallium arsenide |
lekt. dr. Rimantas KNIZIKEVIČIUS |
state-funded |
| Ultrasensitive sensors for the detection of Lithium Ion Batteries fails |
prof. habil. dr. Sigitas TAMULEVIČIUS |
state-funded |
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Charge transfer mechanisms in directly synthesized graphene heterojunctions and their application for bio- and photosensors
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vyr.m.d. dr. Šarūnas MEŠKINIS |
state-funded |
Research Topic Summary.
Graphene is a 2D nanocarbon material, carbon atomic hexagons monolayer. It is at the top of the significant interest due to the giant electron and hole mobility, charge carrier multiplication, flexibility, optical transparency, chemical inertness and other outstanding properties. One of the possible applications of the graphene is use of the graphene in Schottky contacts instead of the metal. Due to the very high mobilities the graphene can be used as a channel layer in field effect transistors and transistor based biosensors. Till now graphene was usually synthesized by chemical vapor deposition of the graphene on catalytic Cu, Ni, Co foils. Afterward, the long process of the graphene transfer onto the targeted semiconductor or dielectric substrates was used. It is a complex and time consuming procedure. Control of the graphene/semiconductor contact and graphene nanolayer properties are complicated in such a case. In present study graphene will be directly synthesized on the semiconductor surface by plasma assisted processes on semiconducting and dielectric substrates. The research aims to study the charge transfer in directly-synthesized graphene and physical processes effects on graphene-based biosensors and photosensors.
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| Modification of surface properties of alloys by atomic beam irradiation |
prof. habil. dr. Arvaidas GALDIKAS |
state-funded |
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Formation and investigation of thin film superclattice of multiferroic magnetoelectrics
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doc. dr. Vytautas STANKUS |
state-funded |
Research Topic Summary.
The new millennium has begun to pay close attention to new materials. Many sensors, controlling devices that transform information and energy are already being successfully used. One class of such materials is inorganic complex metal oxides with so-called active dielectric properties. It are substances which transform various physical effects (mechanical, thermal, radiative, light, electric or magnetic, etc.) into an electrical signal which can be recorded. In addition, these materials have the opposite effect - when exposed to an electric field, they change their state - ferroelectric, ferroelastic, electrostriction, pyroelectric, magnetoelectric, electro-optical, electrocaloric and other phenomena are observed. For a long time in the world of science and technology, these materials have been emphasized as necessary for ferromagnetics or ferroelectrics. However, the first multiferroic material with ferroelectric and (albeit weak) ferromagnetic properties was synthesized in 2003, bismuth ferrite BiFeO3 (BFO). The combined effect of having both properties (both ferroelectric and ferromagnetic at room temperature) was discovered only in 2014. Using ferromagnetic additional layers, a team of scientists from the United States developed a multilayer superlattice structure with magnetoelectric properties. These properties make it possible to look at these materials as a completely new type of memory cell, the magnetization (and direction) of which can only be changed by an electric field. Due to the residual magnetization effect, the storage of information in these memories will not require energy support. The proposed research on this topic will be carried out by synthesizing multiferroic magnetoelectric layers by reactive magnetron sputter deposition. Structures consisting of ferroelectric and ferromagnetic layers will be formed and the magnetoelectric effect will be investigated.
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The investigation and formation by physical vacuum techniques of thin-film structures used in medium temperature solid-state oxide fuel cells
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prof. dr. Giedrius LAUKAITIS |
state-funded |
Research Topic Summary.
The main goal of this work is to find new technological solutions to produce thin-film SOFC with a focus on the currently existing new architectures. Possibilities of various thin layers obtaining technologies for thin film SOFC formation using physical vacuum technologies will be analyzed there.
This research will aim to select the best materials, synthesizing not in a group of analyzed lanthanum strontium gallium magnesium oxide (LSGM) La0.80Sr0.20Ga0.80Mg0.20O3-X and technologies and the influence of technological parameters on the formation of SOFC heterostructures, which will allow improving the efficiency of such fuel cells.
The research objects of the work are: a) the influence of impurities on the properties of the layers; the influence of the composition and technological parameters on the ionic properties of the layers; b) the influence of charge carrier diffusion coefficient and their mobility on ionic properties. Thin ionic layers will be formed using physical vacuum technology. The goal of the survey is to find out and control the physical, chemical, and other properties of thin layers and, on the basis of research, to determine the practical application of such systems.
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Light-activated sensors based on metal oxide nanoparticle investigation
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dr. Simas Račkauskas |
state-funded |
Research Topic Summary.
In this work, the surface of metal oxide nanoparticles (ZnO, CuO) will be functionalized (with nanoparticles, graphene, maxene) in order to obtain room temperature light-activated sensors. Their physical properties, such as the change of the barrier layer due to exposure to light and surface adsorption, will be investigated.
Semiconducting metal oxide nanowires are widely used in sensors due to their tunable electron transport properties and high surface-to-volume ratio. Nanowire sensors have previously been shown to have much higher stability compared to other nanoparticle counterparts. High sensitivity and stability can be obtained by integrating many nanowires, the diameter of the nanowire has a great influence on the performance of the sensor. However, metal oxide gas sensors require high operating temperatures (typically 300–500 °C), but their limited selectivity for similar gases limits their application in real-world situations. Light activation has been shown to be an alternative to heat activation, opening room temperature sensor measurement possibilities, but with lower sensitivity and selectivity compared to heating activation.
ZnO nanowires are often used for chemiresistive sensing due to their many advantages, such as high sensing response and long-term stability. Among other structures, ZnO tetrapods (a structure composed of 4 connected nanowires) are also interesting for chemiresistive sensing and have been used in UV sensing and gas sensors. The high surface-to-volume ratio and porosity of ZnO nanostructures can contribute to the development of a room-temperature gas sensor. In our laboratory, a breakthrough in ZnO sensors was recently obtained, and a record level of sensitivity was demonstrated.
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