A5049116865- Ferroelectric and Piezoelectric Materials
- Microwave Dielectric Ceramics Synthesis
- Multiferroics and related materials
- Acoustic Wave Resonator Technologies
- Dielectric properties of ceramics
- Dielectric materials and actuators
- Electronic and Structural Properties of Oxides
- Solid-state spectroscopy and crystallography
- Photorefractive and Nonlinear Optics
- Thermal Expansion and Ionic Conductivity
- Optical and Acousto-Optic Technologies
- Glass properties and applications
- Nuclear materials and radiation effects
- Geophysics and Sensor Technology
- Material Science and Thermodynamics
- Advanced ceramic materials synthesis
- Gas Sensing Nanomaterials and Sensors
- Advanced Thermoelectric Materials and Devices
- Thermodynamic and Structural Properties of Metals and Alloys
- Transition Metal Oxide Nanomaterials
- Mechanical and Optical Resonators
- Advanced Energy Technologies and Civil Engineering Innovations
- Material Dynamics and Properties
- Magnetic and transport properties of perovskites and related materials
- Material Properties and Failure Mechanisms
University of Agriculture in Krakow
2021-2025
Uniwersytet Komisji Edukacji Narodowej w Krakowie
2012-2021
Institute of Physics
2008-2021
Vilnius Gediminas Technical University
2020
Center for Physical Sciences and Technology
2020
Pedagogical University
1997-2019
University of Silesia in Katowice
2013
Technical University of Darmstadt
2008
Czech Academy of Sciences, Institute of Physics
1990-2001
Abstract Local maxima and other singularities distinguish the temperature range 200-320°C in electrostrictive versus graph of Na0.5Bi0.5TiO3, known from experiments as a region coexistence phases. Investigation pyroeffect virgin Na0.5Bi0.5TiO3 single crystals reveals existence polar microregions.
Infrared reflectivity, time-domain terahertz transmission, high-frequency dielectric measurements and Raman spectroscopy of Na0.5Bi0.5TiO3 complex ferroelectric perovskite were performed in a broad temperature range. The results analysed considering the macroscopic symmetry as well resulting from local Na–Bi ordering all three known phases. An overdamped infrared soft mode was revealed THz range which, together with central-mode type dispersion GHz range, contribute to strong permittivity...
X-ray investigations of Na05Bi0.5TiO3 crystals showed the coexistence rhombohedral and tetragonal phases in wide temperature range. The dependence phase concentrations can explain anomaly dielectric properties observed at 280°C 320°C temperatures.
Lead-free Na0.5Bi0.5TiO3 -BaTiO3 ceramics have been prepared in the whole range of concentrations and studied at room-temperature by means X-ray, Raman scattering infrared techniques. X-ray measurements revealed rhombohedral, rhombohedral-tetragonal boundaries tetragonal modifacations depending on contents BaTiO3. The distinct changes spectra with increasing BaTiO3 content, which were correlated results, observed. broad phonon indicated disorder A site system.
The purpose of the present study was to learn morphological, structural, ferroelectric, dielectric, electromechanical, magnetoelectric, and magnetic properties, DC conductivity BaTiO3-Ni0.64Zn0.36Fe2O4 (BT-F) multiferroic composites compacted via free sintering method. influence ferrite content in ceramic composite materials on functional properties is investigated discussed. X-ray diffraction studies confirmed presence two main phases composite, with strong reflections originating from...
Abstract The dielectric dispersion and influence of a.c. electric field strength on permittivity as well the hysteresis loops for Na0.5Bi0.5TiO3 ceramics were investigated. dipolar relaxation Cole—Cole type below 1 MHz is observed. This significantly evolves with temperature connected dynamics polar regions. increasing shifts characteristic towards lower temperatures. effect can be associated reactivation reversal regions mechanical stresses rising because external action. Examination...
Abstract Performed measurements showed that in Na0.5Bi0.5TiO3 single crystals the long-time variation of electric permittivity is connected with existence polar regions. The size and dynamics regions change temperature. These may be ordered an external field.
Abstract Lead-free Na 0.5 Bi TiO 3 (NBT) ceramics were prepared via a conventional oxide-mixed sintering route and their electrical transport properties investigated. Direct current (DC, σ DC ) alternating (AC, AC conductivity values, polarization (first measurements) depolarization current, current–voltage ( I – U characteristics measurements), the Seebeck coefficient (α) determined under various conditions. The mechanism of phenomena observed for investigated samples found to be typical....
Piezoelectric properties of Na0.5Bi0.5TiO3 ceramics have been investigated over a broad temperature range using resonance technique. The thermal behaviours the piezoelectric tensor coefficients d31, d33 and d15 confirm that there is distinct phase transformation at 200 °C. For first time it has found signal connected with component observed up to 280 This corresponds earlier neutron x-ray diffraction data on point transition from rhombohedral tetragonal symmetry.
Abstract The existence of polar regions in Na0.5Bi0.5Tio3 and pyroelectric measurements. Both dynamics sizes these depend on temperature time.
The single crystals of lead-free Na0.5Bi0.5TiO3 were grown using the Czochralski method. energy gaps determined from X-ray photoelectron spectroscopy (XPS) and optical measurements approximately 2.92 eV. current-voltage characteristics, depolarization current, dc (σdc) ac (σac) electrical conductivity, Seebeck coefficient investigated. frequency/temperature-dependent properties also measured analyzed through complex impedance spectroscopy. An overlapping reversible insulator-metal transition...
Abstract The dielectric, pyroelectric, electrostrictive, optical and thermal properties of Na0.5Bi0.5TiO3, in wide temperature range, particularly the range 200–340[ddot]C are presented discussed. results investigations show complicated nature phase transition occurring this material. Key Words: Sodium-bismuthe titanatepolar regionsrelaxor ferroelectric
It was shown that axial pressure strongly changes the dielectric and ferroelectric properties of Na 0.5 Bi TiO 3 ceramic. This includes: (i) shift rhombohedral-tetragonal phase transition to higher temperature, suppressing dispersion, reduction thermal hysteresis electric permittivity which can be evidence nature second order one, (ii) decrease polarization in long-range decay temperature temperature. Also thermodynamic parameters were estimated.
Lead-free Ba1−xSrxTiO3 (BST) (x = 0, 0.1, 0.2, 0.3, 0.4 and 0.45) ceramics were successfully prepared via the solid-state reaction route. A pure perovskite crystalline structure was identified for all compositions by X-ray diffraction analysis. The basic phase transition temperatures in these studied over a wide temperature range. change symmetry from tetragonal to cubic detected, which further proven phonon anomalies composition/temperature-dependent Raman spectra. incorporation of Sr2+...