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We explore ferroelectric properties of cleaved 2-D flakes of copper indium thiophosphate, CuInP2S6 (CITP), and probe size effects along with limits of ferroelectric phase stability, by ambient and ultra high vacuum scanning probe microscopy. CITP belongs to the only material family known to display ferroelectric polarization in a van der Waals, layered(More)
We report intense terahertz emission from lead zirconate titanate (PZT) tubular nanostructures, which have a wall thickness around 40 nm and protrude on n-type Si substrates. Such emission is totally absent in flat PZT films or bulk; hence the effect is attributed to the nanoscale geometry of the tubes. The terahertz radiation is emitted within 0.2 ps, and(More)
We have investigated the dielectric response of Ba(2)Pr(x)Nd(1-x)FeNb(4)O(15) ceramics (x = 0, 0.2, 0.5, 0.6, 0.8, 1) in the frequency range from 20 Hz to 1 GHz. The obtained results confirmed the continuous transformation from the ferroelectric behavior of Ba2NdFeNb4O15 to the pure relaxor response of Ba(2)PrFeNb(4)O(15) with increasing x. For intermediate(More)
Composite materials based on epoxy resin filled with various kinds of graphite particles: exfoliated graphite (EG), natural graphite, and coarse, medium and fine artificial graphites have been prepared. The dielectric permittivity strongly increases with graphite particle size. This effect is related to the distance of the investigated filler concentrations(More)
The dielectric properties of Polymethylmetacrylate (PMMA) composites filled with CVD made multiwalled carbon nanotubes (MWCNT) of different mean outer diameters (d - 9 nm and 12-14 nm) were investigated at temperatures from 300 K to 390 K and in a wide frequency range (20 Hz-1 MHz). The percolation threshold is lower in composites with thick nanotubes.(More)
Dielectric investigations of pure and diamagnetically substituted Bi<inf>1-x</inf>AE<inf>x</inf>FeO<inf>3</inf> (AE = Ca, Ba, Sr; x=0.1, 0.3) has been carried out. It has been shown that high conductivity of bismuth ferrite is due to movement of oxygen vacancies. Replacement of bismuth by barium, calcium or strontium increases the activation energy of the(More)
We report temperature-dependent electric, IR and Raman studies of niccolite-type formate frameworks templated by protonated 1,4-diaminobutane. Our results show that the zinc-analogue exhibits a first-order phase transition close to 240 K. Single-crystal dielectric data show a much stronger anomaly at the phase transition for ε' along the a-direction(More)
Dielectric measurements of PbMg1/3Nb2/3O3 (PMN) powder and dense ceramics with grain sizes between 15 nm and two microns were carried out in a broad frequency range (20 Hz-1 GHz). Clear grain size dependence of relaxor behavior was evidenced. A progressive transformation from Vogel-Fulcher behavior towards the Arrhenius process in the PMN with reduction of(More)
A set of epoxy resin composites filled with 0.25-2.0 wt.% of commercially available ENSACO carbon black (CB) of high and low surface area (CBH and CBL respectively) has been produced. The results of broadband dielectric spectroscopy of manufactured CB/epoxy below the percolation threshold in broad temperature (200 K to 450 K) and frequency (20 Hz to 1 MHz)(More)
Ultrasonic, dielectric and piezoelectric studies of lead free ceramic system structures of (1-x) BaTiO3-xLa(Mg1/2Ti1/2)O3 (BTLMT) are presented in this contribution. It was shown, that such materials with x=0.025, 0.05, 0.075 and 0.1 LMT content undergo phase transitions and exhibit piezoelectric effect in the low temperature phases. Anomalies of ultrasonic(More)