The beneficial effects of lanthanide incorporation into 0.94Na0.5Bi0.5TiO3-0.06BaTiO3 (BNT-BT) matrix on its functional properties were investigated. conventional solid-state method was used for synthesizing samples. structural refinement revealed that all samples crystallized in R3c rhombohedral symmetry. Raman spectroscopy study carried out using green laser excitation and no clear perceptible variation frequency is observed. Dielectric measurements unveiled the introduction rare earth...

Direct and indirect studies of the electrocaloric effect were carried out in poled depoled Na0.5Bi0.5TiO3. For this purpose, polarization temperature change measurements made at different electric field pulses as a function temperature. The applicability widely used determination method, using Maxwell relation, was critically analyzed with respect to reliable direct measurements. Quantitative differences observed between results obtained by both approaches case Na0.5Bi0.5TiO3 sample. These...

Despite wide studies of Na0.5Bi0.5TiO3, structure this material and its connection with the observed physical properties still raise numerous questions due to mutually contradicting results obtained. Here, dielectric poled unpoled Na0.5Bi0.5TiO3-CaTiO3 solid solutions are studied, projecting obtained concentration dependence on pure Na0.5Bi0.5TiO3 as end member group. X-ray diffraction patterns for reveal dominating an orthorhombic Pnma phase, even compositions approaching composition...

Abstract Precision x-ray studies, polarization and electrocaloric measurements have been made with PST-PSN solid solutions in the temperature range −180–+80°C. The large effect δT = 1.0–1.7°C is due to both particular features of structure rearrangement at 1-order phase transition materials a high ion ordering sublattice B perovskite ABO3.

The existing situation in prospects of application electrocaloric effect (ECE), related to finding ferroelectrics exhibiting high values ECE, is discussed. Besides 1st order ferroelectric-paraelectric phase transitions, which were most promising till recent time with respect there are other approaches, ECE field range relaxors and polymers. restrictions traditional indirect evaluation

Dielectric properties, polarization and x-ray diffraction are studied for (1-x)Na1/2Bi1/2TiO3-xBaTiO3 solid solutions in a concentration range above the morphotropic phase boundary. It is showed that all compositions have tetragonal structure with maximal tetragonality slightly Ferroelectric relaxor behavior observed wide of BaTiO3. Stability state decreases increasing BaTiO3 concentration, but only low Na1/2Bi1/2TiO3 content normal ferroelectric-paraelectric transition, which characteristic...

ABSTRACT Studies of nature polarization in ternary solid solutions Na1/2Bi1/2TiO3-SrTiO3-PbTiO3 were done, using measurements dielectric properties and hysteresis loops. Various stages relaxor behavior depending on concentration PbTiO3 established compared with other known ferroelectric relaxors. Keywords: NBTrelaxorssolid

The electrocaloric effect in rhombohedral PLZT ceramics is studied as function of applied field and temperature. results obtained are consistent with the general idea existence an intermediate state mixed polar nonpolar regions interval diffuse phase transition. step-like change temperature at field-induced first-order transition range close to Tt corresponds entropy jump 0.18 × 10-2 J/cm3 · deg.

Abstract All sequential steps of transfer from relaxor to normal ferroelectric phase transition are found in Na1/2Bi1/2TiO3-SrTiO3-PbTiO3 if concentration PbTiO3 increases. The properties solid solutions described by the power law and Vogel-Fulcher relationship. Concentration dependence relevant parameters is discussed. Stability phases discussed analyzing behaviour critical electric fields. Keywords: NBTrelaxorssolid

Results of the electrocaloric effect (ECE) studies Pb(Sc0.5Nb0.5)O3 ceramic in temperature range from 320 to 400 K are reported. A great value (ΔTmax = 0.9 K) is observed. The and field dependence ECE consistent with presumption a polar nonpolar phase mixing at temperatures above dielectric constant maximum temperature. can be attributed polarization regions, which hardly affected by electric field. Es werden die Ergebnisse der Untersuchung des elektrokalorischen Effekts (EKE)...

Abstract In the present work, Na 0.5 Bi TiO 3 (NBT) ceramics with addition of excess in two different ways – before calcination and sintering are considered, revealing how affects their microstructure chemical content. Average grain size is seen to decrease, distribution becoming less diffused at higher concentrations. The reason for such a feature shift temperature region where abnormal growth starts contribute towards temperatures. influence more pronounced case if it added calcination. It...

Abstract Field induced deformation and electrocaloric effect are investigated in the vicinity of phase transition at 163°C. The sharp increase electrostriction below Tc is explained by field ferroelectric to antiferroelectric transition. appears remains stable absence field. Elastic compliance thermal expansion as functions temperature studied.

Abstract Electrocaloric effect is studied in a group of triple solid solutions 0.4Na1/2Bi1/2TiO3-(0.6-y)SrTiO3-yPbTiO3. Contribution electric field-induced phase transition the total value temperature change, caused by field, evaluated. The highest electrocaloric observed for composition 0.4Na1/2Bi1/2TiO3-0.4SrTiO3-0.2PbTiO3, which depolarization temperature, characteristic relaxor ferroelectrics, merges with maximum dielectric permittivity. Applicability thermodynamic description discussed....

Abstract Optical spectra and dielectric parameters are used to study PLZT X/65/35 (X=4.5−11 at.% La) PSN ceramics subject gamma- electron-, neutron irradiation. In neutron-irradiated stable defects, maintained at annealing up 700 °C manifested by a gradual shift of extinction edge near the fundamental absorption longer wavelengths reduced polarization values. The thermal dependence in reference samples has been determined be ca. 0.10 nm/deg (0.9 meV/deg) 0.125 nm/deg, respectively range...

Abstract Continuous transfer from relaxor to normal ferroelectric phase transition is found in Na 1/2 Bi TiO 3 ‐SrTiO ‐PbTiO if concentration of PbTiO increases. The properties NBT solid solutions are described by the power law and Vogel‐Fulcher relationship, dependence relevant parameters discussed. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Abstract Structural rearrangements in lead-containing (A‘A’) (B’B“)O3 type perovskite compounds are caused by technological treatment, high-energy radiation and ambient conditions. Variation of structure ordering along with modification (substituted or defected solid solutions) may provide promising compositions for applications, e.g., cascade microcryogenic devices (PST solutions); efficient piezoelectric materials – here the new (1 x)Pb(Lu1/2Nb1/2)O3 xPbTiO3 system morphotropic region. The...

The long and short range orders in 0.4Na1/2Bi1/2TiO3-(0.6-x)SrTiO3-xPbTiO3 solid solutions were studied by x-ray diffraction Raman spectroscopy. X-ray patterns for these compositions the relaxor state are different bulk powdered samples. It was found that, spite of tetragonality depending on PbTiO3 content, spectra suggest similarity local structure all compositions. Both methods indicate a disappearance tetragonal phase upon increasing temperature.

The complete set of elastic constants the single crystal [N(${\mathrm{CH}}_{3}$${)}_{4}$${]}_{2}$${\mathrm{MnCl}}_{4}$ has been measured at 15 MHz in temperature range 250--310 K, including normal-incommensurate transition ${\mathit{T}}_{\mathit{I}}$=292.3 incommensurate-improper ferroelastic lock-in ${\mathit{T}}_{\mathit{L}}$=291.7 and improper ferroelastic--improper ${\mathit{T}}_{1}$=266.7 K. Landau theory used to explain experimental data. In addition, attenuation longitudinal wave...

Phase coexistence region is studied by x-ray diffraction for Na1/2Bi1/2TiO3-BaTiO3 solid solutions in the tetragonal phase side from morphotropic boundary. The first order ferroelectric transition, determined a jump temperature dependence of dielectric permittivity, located inside cubic and phases below temperature, where tetragonality disappears. At low BaTiO3 concentrations transition into state at cooling slowly approached time smeared over large range. Rietveld method, applied more...

Morphotropic phase boundary of ferroelectric solid solutions attracts interest with respect to not only improved piezoelectric properties but also the electrocaloric effect, which is attractive build new-generation cooling devices. In present study, effect in (1 − x y)Na0.5Bi0.5TiO3–xBaTiO3–yNaNbO3 near its morphotropic studied by direct measurements temperature change ΔT. ΔT maximum observed region depolarization temperature, where major contribution comes from an entropy jump at electric...