A5084561137- Ferroelectric and Piezoelectric Materials
- Solid-state spectroscopy and crystallography
- Microwave Dielectric Ceramics Synthesis
- Acoustic Wave Resonator Technologies
- Multiferroics and related materials
- Dielectric materials and actuators
- Electromagnetic wave absorption materials
- Dielectric properties of ceramics
- Crystal Structures and Properties
- Perovskite Materials and Applications
- Glass properties and applications
- Conducting polymers and applications
- Optical and Acousto-Optic Technologies
- Advanced Sensor and Energy Harvesting Materials
- Photorefractive and Nonlinear Optics
- Phase-change materials and chalcogenides
- Material Dynamics and Properties
- Nonlinear Optical Materials Research
- Advanced NMR Techniques and Applications
- Metal-Organic Frameworks: Synthesis and Applications
- Polymer Nanocomposites and Properties
- Carbon Nanotubes in Composites
- X-ray Diffraction in Crystallography
- Material Properties and Applications
- Smart Materials for Construction
Vilnius University
2016-2025
Yonsei University
2021
Polish Academy of Sciences
2017-2021
Wrocław University of Science and Technology
2021
AGH University of Krakow
2021
Thomas Young Centre
2021
Imperial College London
2021
University of Aveiro
2014-2020
Uzhhorod National University
2020
Weizmann Institute of Science
2019
We explore ferroelectric properties of cleaved 2-D flakes copper indium thiophosphate, CuInP2S6 (CITP), and probe size effects along with limits phase stability, by ambient ultra high vacuum scanning microscopy. CITP belongs to the only material family known display polarization in a van der Waals, layered crystal at room temperature above. Our measurements directly reveal stable, as evidenced domain structures, switchable polarization, hysteresis loops. found that structure thicker than 100...
Abstract Due to the unprecedented rapid increase of their power conversion efficiency, hybrid organic–inorganic perovskites CH 3 NH PbX (X = I, Br, Cl) can potentially revolutionize world solar cells. However, despite tremendous research activity, origin exceptionally large diffusion length photogenerated charge carriers, that is, low recombination rate, remains elusive. Using frequency and temperature‐dependent dielectric measurements across entire spectrum, it is shown constant conserves...
Formation of noncentrosymmetric three-dimensional (3D) lead halide perovskites has been a widely sought after goal because the polar structure opens up new vistas to properties these materials, e.g., improved charge separation for photovoltaics arising from ferroelectric order. Here, we report growth and unique highly distorted 3D perovskite, methylhydrazinium chloride (CH3NH2NH2PbCl3, MHyPbCl3). This perovskite crystallizes in P21 at room temperature, which consists two types PbCl6...
Abstract Polar van der Waals chalcogenophosphates exhibit unique properties, such as negative electrostriction and multi-well ferrielectricity, enable combining dielectric 2D electronic materials. Using low temperature piezoresponse force microscopy, we revealed coexistence of piezoelectric non-piezoelectric phases in CuInP 2 Se 6 , forming unusual domain walls with enhanced response. From systematic imaging experiments have inferred the formation a partially polarized antiferroelectric...
The dielectric dispersion of the transparent relaxor ferroelectric ceramics PLZT 8/65/35 and 9.5/65/35 was determined in a wide frequency range including microwave infrared range. number observed polar phonons spectra gives evidence about locally broken cubic symmetry presence nanoclusters whole investigated temperature up to 530 K. A single broad symmetric that occurs below phonon frequencies fitted with Cole-Cole formula uniform distribution Debye relaxations. On decreasing temperature,...
For a deuterated solid solution of 15% antiferroelectric betaine phosphate (BP) and 85% ferroelectric phosphite (BPI), measurements the dielectric permittivity at frequencies 20 Hz< <1 MHz are reported. The freezing phenomena in DBP0.15 DBPI0.85reveal characteristics transition into dipolar glass state with peculiarities due to quasi-one-dimensional structure. Using Kutnjak model temperature 25 K is estimated for DBPI0.85and one 10 protonated BP0.15 DBPI0.85 . relaxation time distribution...
A comprehensive analysis of electrical, electromagnetic (EM), mechanical, and thermal properties epoxy resin composites filled with 0.25–2.0 wt. % carbon additives characterized by high surface area, both nano-sized, like nanotubes (CNTs) black (CBH), micro-sized exfoliated graphite (EG), was performed. We found that the physical CNTs- CBH-based increased all together filler content even more clearly for CBH than CNTs. In case EG-based composites, good correlation between amount observed...
Abstract Cation engineering provides a route to control the structure and properties of hybrid halide perovskites, which has resulted in highest performance solar cells based on mixtures Cs, methylammonium, formamidinium. Here, we present multi-technique experimental theoretical study structural phase transitions, phases dipolar dynamics mixed methylammonium/dimethylammonium MA 1- x DMA PbBr 3 perovskites (0 ≤ 1). Our results demonstrate significant suppression enhanced disorder...
Structural transformations of CsPbBr 3 were studied by multiple techniques (dielectric, Raman, EPR spectroscopy and XRD) in an extended temperature range.
Hybrid organic-inorganic lead halide perovskites are promising candidates for next-generation solar cells, light-emitting diodes, photodetectors, and lasers. The structural, dynamic, phase-transition properties play a key role in the performance of these materials. In this work, we use multitechnique experimental (thermal, X-ray diffraction, Raman scattering, dielectric, nonlinear optical) theoretical (machine-learning force field) approach to map phase diagrams obtain information on...
To address the ever-increasing electromagnetic interference (EMI) pollution, a hybrid filler approach for novel composites was chosen, with focus on EMI absorbance. Carbon nanofiller loading limited to 0.6 vol.% in order create sustainable and affordable solution. Multiwall carbon nanotubes (MWCNT) iron oxide (Fe3O4) nanoparticles were mixed nine ratios from 0.1 8.0 12.0 vol.%, respectively. With addition of surfactant, excellent particle dispersion achieved (examined SEM micrographs)...
This work presents the dielectric and ultrasonic properties of polydimethylsiloxane (PDMS) nanocomposites filled with titanium dioxide nanoparticles. The study was performed over a very broad range frequencies (20 Hz–3 THz). permittivity almost frequency-independent in all composites at room temperature whole measurement frequencies, losses were low under these conditions (less than 2). strongly increases nanoparticle concentration according to Maxwell–Garnet model. Therefore, investigated...
The structure of TlGaSe2 has been studied by triple-crystal X-ray scattering techniques. At room temperature in the paraelectric phase is believed to be C2/c, but authors found that some (h, h, l) Bragg reflections, those with h odd, are broadened along c* direction. This shown arise because faults stacking atomic sheets perpendicular c*. A simple model developed for which suggests on average a fault occurs single crystal about once every four planes. Between 117 and 110 K an incommensurate...
Dielectric relaxation of BaTi1− x Sn O3 ceramics is investigated by means dielectric spectroscopy. The gradual crossover from ferroelectric to relaxor behavior characterized vanishing the contribution due domain walls and appearance related reorientation polar nanosized regions. Typical relaxors observed only in with = 0.30, while compositions 0.175 ≤ 0.25 show coexistence both features. properties are supposed be weak random fields disorder inherent pure BaTiO3.
A central issue in the physics of relaxor ferroelectrics is origin formation polar nanoregions below some characteristic temperature scale. While it often attributed to chemical disorder, random bond--random field appearance, or local symmetry lowering, shown here that huge intrinsic nonlinearity gives rise spatially limited excitations discrete breather (DB) type, which interact strongly and self-consistently with remaining lattice. This scenario corresponds a two-component approach...
The wide application of microwaves stimulates searching for new materials with high electrical conductivity and electromagnetic (EM) interference shielding effectiveness (SE). We conducted a comparative study EM SE in K -band demonstrated by ultra-light micro-structural porous carbon solids (carbon foams) different bulk densities, 0.042 to 0.150 g/cm 3 , conventional flexible epoxy resin filled nanotubes (CNTs) small concentrations, 1.5 wt.%. Microwave probing foams showed that the...
We report synthesis and composite study of a novel metal–organic framework (MOF) compound chemical formula ∞3[Cu2ICu2II{H2O}2{(Me–trz–mba)2thio}2]Cl2, where (Me–trz–mba)2thio2– stands for 3,3-(5,5-(thiophene-2,5-diyl)bis(3-methyl-4H-1,2,4-triazole-5,4-diyl))dibenzoate. This coordination polymer was synthesized by solvothermal synthesis. The crystal structure determined using single X-ray diffraction. main building block this is so-called Cu2 paddle-wheel (PW) unit, which contains two Cu2+...
Three-dimensional methylhydrazinium (CH3NH2NH2+, MHy+) lead halides, related to the famous methylammonium (CH3NH3+, MA+) and formamidinium (CH(NH2)2+, FA) perovskites, are attractive optoelectronic materials crystallizing in polar structures. In this work, temperature-dependent 1H 207Pb magic-angle spinning (MAS) NMR, Raman as well high-pressure studies of CH3NH2NH2PbCl3 (MHyPbCl3) reported. spectroscopy reveals many similarities between phonon properties MHy halides MA FA analogues....