Switching Current in Pb(Zn1/3Nb2/3)O3-PbTiO3 Single Crystals

1999 ◽  
Vol 604 ◽  
Author(s):  
Uma Belegundu ◽  
Xiaohong Du ◽  
Kenji Uchino
Keyword(s):  
Solid Solution ◽  
Barium Titanate ◽  
Single Crystal ◽  
Single Crystals ◽  
Applied Field ◽  
Exponential Dependence ◽  
Polarization Reversal ◽  
Switching Current ◽  
Linear Fit ◽  
Two Phases

AbstractSwitching current measurements have been carried out on relaxorferroelectric single crystal-pure PZN, and the solid solution (1-x) Pb(Zni1/3 Nb2/3)O3 - x PbTiO3 with x= 0.04, 0.09, 0.10. Measurements have been done for crystallographic directions [001] and [111] for all these compositions. Switching times versus the applied field showed the following results. Pure PZN along [111] and 0.90PZN—O. 10PT along [001], and [111] showed an exponential dependence. Along [001] the PZN showed a linear fit. For solid solution single crystals-0.96PZN -0.04PT and 0.91PZN £ 0.09PT, a linear fit was obtained for the reciprocal switch times versus applied field for both the directions. If we draw a parallel picture with the reported barium titanate data, it appears that the polarization reversal is controlled by nucleation along [111]- spontaneous direction for PZN and [001], [111]for 0.90PZN - O.10PT. The mobility of the reversed domains controls the reversal along [001] for PZN and the solid solution single crystals with rhombohedral composition along [001] and [111]. The transient current curves showed two maximum points for crystals with x = 0.04 and 0.09. This is attributed to the co-existence of the two phases in 0.96PZN -0.04PT and 0. 91PZN - 0.09PT crystals.

scholarly journals Precursor Phenomena of Barium Titanate Single Crystals Grown Using a Solid-State Single Crystal Growth Method Studied with Inelastic Brillouin Light Scattering and Birefringence Measurements

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3171 ◽  
Author(s):  
Soo Han Oh ◽  
Jae-Hyeon Ko ◽  
Ho-Yong Lee ◽  
Iwona Lazar ◽  
Krystian Roleder
Keyword(s):  
Crystal Growth ◽  
Solid State ◽  
Barium Titanate ◽  
Single Crystal ◽  
Single Crystals ◽  
Melting Process ◽  
Point Of View ◽  
Crystal Quality ◽  
Cubic Phase ◽  
Growth Method

The nature of precursor phenomena in the paraelectric phase of ferroelectrics is one of the main questions to be resolved from a fundamental point of view. Barium titanate (BaTiO3) is one of the most representative perovskite-structured ferroelectrics intensively studied until now. The pretransitional behavior of BaTiO3 single crystal grown using a solid-state crystal growth (SSCG) method was investigated for the first time and compared to previous results. There is no melting process in the SSCG method, thus the crystal grown using a SSCG method have inherent higher levels of impurity and defect concentrations, which is a good candidate for investigating the effect of crystal quality on the precursor phenomena. The acoustic, dielectric, and piezoelectric properties, as well as birefringence, of the SSCG-grown BaTiO3 were examined over a wide temperature range. Especially, the acoustic phonon behavior was investigated in terms of Brillouin spectroscopy, which is a complementary technique to Raman spectroscopy. The obtained precursor anomalies of the SSCG-grown BaTiO3 in the cubic phase were similar to those of other single crystals, in particular, of high-quality single crystal grown by top-seeded solution growth method. These results clearly indicate that the observed precursor phenomena are common and intrinsic effect irrespective of the crystal quality.

The Effect of Solid Solution Impurities on Dislocation Nucleation in a (001) Mo – 1.5 at.% Ir Single Crystal

2010 ◽  
Vol 662 ◽  
pp. 85-93
Author(s):  
Sergey Dub ◽  
Igor Zasimchuk ◽  
Leonid Matvienko
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Shear Stress ◽  
Elastic Modulus ◽  
Single Crystal ◽  
Single Crystals ◽  
Free Volume ◽  
Dislocation Nucleation ◽  
Initial Portion ◽  
G 12

Mechanical properties of (001) Mo and (001) Mo – 1.5 at.% Ir single crystals have been studied by nanoindentation. It has been found that the iridium addition to molybdenum leads to an increase in both hardness and elastic modulus. An abrupt elasto-plastic transition (pop-in) at a depth of about 20 - 40 nm caused by dislocation nucleation in previously dislocation-free volume has been observed in the initial portion of the loading curve. It has shown that the Ir addition essentially affects the dislocation nucleation. Mean shear stress required for the dislocation nucleation increased from 10.8 GPa (G/12) for a Mo single crystal to 18.2 GPa (G/8) for the Mo – 1.5 at% Ir solid solution. Thus, the Ir solution in a Mo single crystal affects not only the resistance to the motion of dislocations (hardness) but the nucleation of them as well. The latter is likely to occur as a result of an increase in the structure perfection of the Mo – 1.5 at% Ir solid solution as compared to the pure Mo single crystal.

scholarly journals High Field Polarization Reversals in Liquid Electroded Barium Titanate Crystals

1962 ◽  
Vol 15 (4) ◽  
pp. 549 ◽  
Author(s):  
GW Taylor
Keyword(s):  
Barium Titanate ◽  
Constant Velocity ◽  
Applied Field ◽  
High Field ◽  
Polarization Reversal ◽  
Field Range ◽  
Cross Sectional ◽  
Surface Conditions ◽  
Sectional Shape ◽  
Current Transients

The study of the polarization reversal in liquid electroded crystals of barium titanate has previously been mainly restricted to switching fields less than 1� 2 k V fcm. This paper studies the reversal in the field range 1� 5-6 kV fcm. For these higher fields, it is concluded, from switching current transients and " static" domain patterns, that the reversal is achieved by a small number of parallel. sided domains expanding radially sidewise at a constant velocity. All the domains appear to begin growing when the field is first applied. The cross-sectional shape of the domains varies from circular at fields greater than 3 kVfcm to square at fields less than 3 kVfcm. The number and distribution of the domain centres is determined by the surface conditions of the crystal, where the electrodes are situated, and not by the applied field.

Investigation of polarization reversal and analysis of switching current data in KTP single crystals

2017 ◽  
Vol 508 (1) ◽  
pp. 1-8 ◽  
Author(s):  
A. R. Akhmatkhanov ◽  
E. M. Vaskina ◽  
M. A. Chuvakova ◽  
E. V. Pelegova ◽  
V. Ya. Shur
Keyword(s):  
Single Crystals ◽  
Current Data ◽  
Polarization Reversal ◽  
Switching Current

scholarly journals Analysis of Switching Current Data during Polarization Reversal in KTP Single Crystals with Surface Dielectric Layer

Crystals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 315 ◽  
Author(s):  
Andrey Akhmatkhanov ◽  
Ekaterina Vaskina ◽  
Ekaterina Gachegova ◽  
Vladimir Shur
Keyword(s):  
Single Crystals ◽  
Dielectric Layer ◽  
Domain Walls ◽  
Current Data ◽  
Domain Growth ◽  
Structure Evolution ◽  
Polarization Reversal ◽  
Switching Current ◽  
In Situ Visualization

Studies of polarization reversal processes in potassium titanyl phosphate (KTiOPO4, KTP) single crystals with surface dielectric layer are important due to their potential applications as the basis of bottom-up technology for creation of periodically poled nonlinear-optical crystals. We present the results of switching currents analysis accompanied by in situ visualization of domain kinetics during polarization reversal in KTP with 3 m-thick photoresist dielectric layer. Qualitative change of the switching current shape has been revealed as compared to the polarization reversal without surface dielectric layer. Two stages of domain structure evolution have been distinguished by in situ visualization of domain kinetics. The formation of submicron domain streamers in front of the moving domain walls has been revealed. The broadening of the domain streamers (1D domain growth) was observed at the second stage. The switching currents were approximated by the modified Kolmogorov-Avrami formula taking into account the change of the growth dimensionality (“geometrical catastrophe”). The sufficient input of the 1D growth to the switching process decreased with increase of the switching field. The obtained results were attributed to the domain wall shape instability induced by retardation of the depolarization field screening in ferroelectric with surface dielectric layer.

Enhanced Piezoelectric Properties of Barium Titanate-Potassium Niobate Solid Solution System Ceramics by MPB Engineering

2010 ◽  
Vol 445 ◽  
pp. 11-14 ◽  
Author(s):  
Shigehito Shimizu ◽  
Petr Pulpan ◽  
Nobuhiro Kumada ◽  
Daisuke Tanaka ◽  
Masahito Furukawa ◽  
...  
Keyword(s):  
Solid Solution ◽  
Barium Titanate ◽  
Piezoelectric Property ◽  
Potassium Niobate ◽  
Interface Area ◽  
Solution System ◽  
Solid Solution System ◽  
Conventional Sintering ◽  
Two Phases ◽  
Sintering Method

Barium titanate (BaTiO3, BT) - potassium niobate (KNbO3, KN) solid solution system (0.5BT-0.5KN) ceramics with various microstructures were prepared by conventional sintering method and two-step sintering method using BT and KN nanoparticles. Their microstructures were investigated using X-ray diffraction (XRD) measurement and scanning electron microscopy (SEM), and it was confirmed that two ferroelectric phases, i.e., BT-rich tetragonal and KN-rich orthorhombic phases, always coexisted for all ceramics, which suggested that 0.5BT-0.5KN ceramics had “pseudo-morphotropic phase boundary (MPB)” structure. Thus, the control of the interface area between two phases was important to enhance piezoelectric property. Finally, their piezoelectric property was measured, and the apparent piezoelectric constant d33* increased with increasing interface area.

scholarly journals Подвижность носителей заряда в монокристалле и нанокерамике суперионного проводника Pb-=SUB=-1-x-=/SUB=-Sn-=SUB=-x-=/SUB=-F-=SUB=-2-=/SUB=- (x=0.2)

2019 ◽  
Vol 61 (11) ◽  
pp. 2044
Author(s):  
Н.И. Сорокин
Keyword(s):  
Solid Solution ◽  
Ionic Conductivity ◽  
Single Crystal ◽  
Single Crystals ◽  
Concentration Dependence ◽  
Crystal Form ◽  
Superionic Conductor ◽  
Charge Carriers ◽  
Ion Transfer ◽  
Anionic Charge

AbstractA crystallophysical model of ion transfer in the superionic Pb_1 – _ x Sn_ x F_2 conductor with a fluorite (CaF_2) structure is proposed. The concentration dependence of the ionic conductivity of Pb_1 – _ x Sn_ x F_2 single crystals and poly- and nanocrystals is analyzed. The single-crystal form of the superionic conductor is characterized by the highest conductivity. The mobility and concentration of anionic charge carriers in a single crystal and ceramics of Pb_1 – _ x Sn_ x F_2 ( x = 0.2) is calculated on the basis of structural and electrophysical data. The mobility of carriers μ_mob = 2.5 × 10^–6 cm^2/s V (at 293 K) in a single crystal is seven times higher than in nanoceramic. The concentration of carriers n _mob = 1.7 × 10^21 and 3.6 × 10^21 cm^3 (4.5 and 9.5% of the total number of anions) for a single crystal and nanoceramic, respectively. The comparison of isostructural Pb_0.8Sn_0.2F_2, Pb_0.67Cd_0.33F_2, and Pb_0.9Sc_0.1F_2.1 single crystals shows that anionic carriers have a maximum mobility in the β-PbF_2 and SnF_2 based solid solution.

Anisotropic Magnetization in Single Crystal YBa2Cu3O7

1987 ◽  
Vol 01 (02) ◽  
pp. 401-408 ◽  
Author(s):  
R.N. Shelton ◽  
R.W. McCallum ◽  
M.A. Damento ◽  
K.A. Gschneidner
Keyword(s):  
Magnetic Properties ◽  
Transition Temperature ◽  
Critical Temperature ◽  
Critical Current Density ◽  
Single Crystal ◽  
Single Crystals ◽  
Current Density ◽  
Applied Field ◽  
Hysteresis Loops ◽  
Anisotropic Magnetization

Magnetization measurements on single crystals of YBa2Cu3O7 are used to study the anisotropy of the critical current density and magnetic properties of this superconducting oxide with a transition temperature of 88 K. Anisotropy of the magnetization versus applied field hysteresis loops is pronounced, with the effect increasing as the temperature approaches the superconducting critical temperature.

Investigation of Pu Incorporation into Zircon Single Crystal

2004 ◽  
Vol 824 ◽  
Author(s):  
John M. Hanchar ◽  
Boris E. Burakov ◽  
Maria V. Zamoryanskaya ◽  
Vladimir M. Garbuzov ◽  
Alexander A. Kitsay ◽  
...  
Keyword(s):  
Solid Solution ◽  
Single Crystal ◽  
Single Crystals ◽  
Unit Cell ◽  
Additional Research ◽  
Powdered Sample ◽  
Unit Cell Parameters ◽  
Flux Method ◽  
Cell Parameters ◽  
Zircon Structure

AbstractIn order to obtain Pu-doped zircon, (Zr,Pu)SiO4, with a maximum Pu content in the form of solid solution, zircon single crystals have been grown using the flux method from starting materials overloaded with Pu. The crystals obtained ranged from 0.2-0.5 to 3.5-4.5 mm in size, are transparent, and characterized by deep pink-brown color. No inclusions of separate Pu phases were observed in the crystals. The distribution of Pu in crystals is zoned and the Pu content varying from approximately 5 to 14 wt.% el. The zircon unit cell parameters calculated from XRD data of bulk powdered sample were: a=6.620(1); c=5.989(2). The results obtained allow us to conclude that the capacity of the zircon structure to incorporate Pu exceeds 10 wt.% el.; however, additional research is required to study the extent of solid solution, (Zr,Pu)SiO4, at higher Pu contents.

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