Peculiar properties of phase transitions in Na0.5Bi0.5TiO3−0.06BaTiO3 lead-free relaxor ferroelectrics seen via acoustic emission

2017 ◽  
Vol 10 (04) ◽  
pp. 1750048 ◽  
Author(s):  
Evgeniy Dul’kin ◽  
Jenia Tiagunova ◽  
Evgeny Mojaev ◽  
Michael Roth
Keyword(s):  
Phase Transition ◽  
Acoustic Emission ◽  
Phase Transitions ◽  
Local Maximum ◽  
Relaxor Ferroelectrics ◽  
Lead Free ◽  
Temperature Range ◽  
Ceramic Samples ◽  
M Phase ◽  
High Temperature Maximum

Na[Formula: see text]Bi[Formula: see text]TiO3-0.06BaTiO3 relaxor ferroelectrics (RFEs) ceramic samples were investigated by means of dielectric and acoustic emission methods in the temperature range of 70–350[Formula: see text]C and in dependence on frequency. Dielectric curve exhibits two anomalies: strongly dispersive the local maximum, within 130–180[Formula: see text]C and slightly dispersive the smeared high-temperature maximum within 300–310[Formula: see text]C. Acoustic emission exhibits the five groups of bursts: near 123[Formula: see text]C, 150–180[Formula: see text]C, near 225[Formula: see text]C, 300–310[Formula: see text]C and 327[Formula: see text]C. The first and third groups of acoustic emission bursts correspond to phase transitions of R[Formula: see text]c-P[Formula: see text]bm phases coexisting in this temperature, range, while the fourth and fifth groups of acoustic emission bursts correspond to P[Formula: see text]bm-P[Formula: see text] /mbm-Pm[Formula: see text] m phase transitions. The second group of acoustic emission bursts corresponds to strongly dispersive local maximum at which no phase transition has been proved in Na[Formula: see text]Bi[Formula: see text]TiO3-0.06BaTiO3. The existence and the location of the intermediate temperature, [Formula: see text], in Na[Formula: see text]Bi[Formula: see text]TiO3-0.06BaTiO3 compound are discussed.

scholarly journals Peculiar Properties of Phase Transitions in Na0.5Bi0.5TiO3-xBaTiO3 (0

2018 ◽  
Vol 21 (3) ◽  
Author(s):  
Eveniy Dul'kin ◽  
Jan Suchanicz ◽  
Antoni Kania ◽  
Michael Roth
Keyword(s):  
Acoustic Emission ◽  
Phase Transitions ◽  
Relaxor Ferroelectrics ◽  
Lead Free

Structural-phase transition in (Cu2Te)2−x(ZnTe)x at high temperature

2021 ◽  
pp. 2150113
Author(s):  
H. B. Gasimov ◽  
R. M. Rzayev
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
High Temperature ◽  
Single Crystals ◽  
Structural Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
Xrd Study ◽  
Xrd Method

Cu2Te single crystal was grown by the Bridgman method. X-ray diffraction (XRD) study of Cu2Te single crystals in the temperature range of 293–893 K was performed and possible phase transitions in the mentioned range of temperature have been investigated. (Cu2Te)[Formula: see text](ZnTe)[Formula: see text] single crystals also were grown with [Formula: see text], 0.05, 0.10 concentrations and structural properties of the obtained single crystals were investigated by the XRD method in the temperature range 293–893 K. Lattice parameters and possible phase transitions in the mention temperature range were determined for (Cu2Te)[Formula: see text](ZnTe)[Formula: see text] single crystals for [Formula: see text], 0.05, 0.10 concentrations.

Investigation of the Phase Transition at 67.17 K in the Thiourea-CCl4 Inclusion Compound. As Studied by 14N NQR

1994 ◽  
Vol 49 (1-2) ◽  
pp. 433-438 ◽  
Author(s):  
J. El Ghallali ◽  
M. Gourdji ◽  
L. Guibé ◽  
A. Péneau
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Carbon Tetrachloride ◽  
Inclusion Compound ◽  
Central Line ◽  
Host Lattice ◽  
Central Component ◽  
Two Phase ◽  
Temperature Range ◽  
Calorimetric Measurements

Abstract The 14N NQR from the host lattice of the thiourea-carbon tetrachloride inclusion compound. From calorimetric measurements, two phase transitions are known to occur at 67.2 K and 41.3 K in this compound. Above the 67.2 K transition, the 14N NQR spectrum consists of one resonance, though a small splitting of about 0.5 kHz is seen at temperatures up to ca. 105 K. Below the transition, the resonance appears as a central component, in continuation of the resonance above the transition, and two satellites at + 10 kHz and -8 kHz from the central line. The transition from the single resonance to a fully resolved spectrum takes place in a temperature range of less than one kelvin. The results are compared with those previously obtained with the thiourea-cyclohexane inclusion compound.

Notizen: Austausch von Nitrit- gegen Bromidanionen in Na3NO3 / Replacement of Nitrite by Bromide Anions in Na3NO3

1989 ◽  
Vol 44 (8) ◽  
pp. 996-998 ◽  
Author(s):  
M. Jansen ◽  
W. Müller
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Solid Solutions ◽  
Room Temperature ◽  
Mixed Crystals ◽  
Miscibility Gap ◽  
Temperature Range ◽  
Collective Interactions

Na3O(NO2) and Na3OBr are isostructural and form solid solutions with a miscibility gap χ = 0.28 to 0.62 as referred to Na3OBrx(NO2)1-x, at room temperature. Above 593 Κ formation of mixed crystals was observed for all compositions. In contrast to pure Na3O(NO2), the solid solutions do not undergo any phase transition in the investigated temperature range from 293 Κ to 130 K. These findings reveal that collective interactions between the dynamically disordered NO2--groups are involved in the phase transitions of Na3NO3.

Structural phase transitions in the superionic conductors Na9{Fe2[PO4]4(O, F)2} and Na8{Ti2[PO4]4O2} in the temperature range 520–540 K

1994 ◽  
Vol 209 (8) ◽  
Author(s):  
B. Maximov ◽  
N. Bolotina ◽  
R. Tamazyan ◽  
H. Schulz
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Structural Phase ◽  
Superionic Conductors ◽  
Structural Phase Transitions ◽  
Temperature Range ◽  
Symmetry Change

AbstractThe NaFor NTP crystals, the phase transition in the range 520K-540K is reduced to the disordering of the Na sublattice and gives rise to a symmetry from monoclinic (sp. gr.For NFP crystals, the phase transition in the same temperature range leads to a symmetry change from

scholarly journals Analysis of the Phase Transitions in BNT-BT Lead-Free Ceramics Around Morphotropic Phase Boundary by Mechanical and Dielectric Spectroscopies

2016 ◽  
Vol 61 (1) ◽  
pp. 17-20 ◽  
Author(s):  
P.S. Silva ◽  
J.C.C.A. Diaz ◽  
O. Florêncio ◽  
M. Venet ◽  
J.C. M’Peko
Keyword(s):  
Phase Transitions ◽  
Phase Boundary ◽  
Morphotropic Phase Boundary ◽  
Lead Free ◽  
X Ray Diffraction ◽  
Mechanical Loss ◽  
Temperature Range ◽  
Lead Free Ceramics ◽  
Frequency Independent ◽  
Diffraction Patterns

Abstract In this work, the syntheses and characterization by mechanical and dielectric spectroscopies of (1-x) Bi0.5Na0.5TiO3-xBaTiO3 (BNT-100xBT), with x = 0.05, 0.06 and 0.07, lead-free piezoelectric ceramics is reported. Ceramic samples of BNT-BT have been prepared by mixed-oxide method and then conventionally sintered. X-ray diffraction patterns of sintered samples, indicated for BNT-7BT the presence of tetragonal (P4mm) complex perovskite structure, whereas for BNT-5BT and BNT-6BT the samples exhibit a mixture of tetragonal (P4mm) and rhombohedral (R3c) crystalline phases, which reveal the presence of a morphotropic phase boundary (MPB) in the BNT-BT system. Measurements of internal friction, Q-1, and the storage modulus, E’, as a function of temperature at various frequencies were carried out in a Dynamic Mechanical Analyzer (DMA), in the temperature range from 0ºC to 600ºC. Dielectric profiles are recorded in the frequency range from 1kHz to 100kHz and the temperature range from room temperature to 475ºC. Mechanical loss spectra obtained for investigated compositions of BNT-BT samples showed different frequency-independent anomalies. Two main anomalies for BNT-5BT and BNT-6BT, observed around 100ºC and 430ºC were associated with the ferroelectric-antiferroelectric and antiferroelectricparaelectric phase transitions, respectively. The results obtained from mechanical loss measurements were supported by dielectric relaxation spectra. For BNT-7BT, outside the MPB, four different frequency-independent processes were observed.

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